Modular film sensors with record memry for modular automated diagnostic apparatus

ABSTRACT

A modular automated diagnostic analyzer having a fluid entry module for sample aspiration, a valve module for selecting fluids and a pump module for fluidic movement. so that a biological sample does not come into contact with the valve system through which calibrants and air are introduced to the fluid path. The fluid entry module encloses an aspiration tube rotatably and slidably engaged with the analysis mechanism chassis to move to different positions for the introduction of fluids into the analysis apparatus from different types of sample containers. A wiping seal removes residues of aspirated fluids from the exterior surfaces of the aspiration tube with the residue being aspirated into the analysis apparatus for disposal. Sensor modules mounted in a sensor chamber are structured to mechanically stack and interlock and include film sensors with use life record memories and each sensor module includes a fluid tight sealed passage and a sensor element. A fluid selection valve of highly polished ceramic material allows a valve cylinder passage to be selectively connected to fluid sources. A self-contained reagent pouch housing contains calibrants including tonometered calibrants in reagent pouches wherein each pouch wall includes multiple layers of materials wherein at least one layer is a thin, flexible glass material. The walls are extended to form a filler neck sealed by heat and pressure along a sealing line below a filler line so that no bubbles are trapped in the reagent pouch.

CROSS REFERENCES TO RELATED APPLICATIONS

[0001] The present Patent Application is a Continuation In PartApplication of co-pending Pat. application Ser. No. 09/663,719, filedSep. 15, 2000 and since allowed, which is a Divisional PatentApplication of Pat. application Ser. No. 09/350,054, filed Jul. 8, 1999and since allowed, which in turn is a Divisional Patent Application ofPat. application Ser. No. 09/118,683, filed Jun. 30, 1998 and sinceallowed, which in turn claims benefit of U.S. Provisional ApplicationNo. 60/053,265, filed Jul. 21, 1997, all by the same inventors as thepresent Application and directed to the same invention and containingthe same disclosure as the present Application. The present PatentApplication claims benefit of prior Pat. application Ser. No. 09/118,683and of U.S. Provisional Application No. 60/053,265, which areincorporated herein by reference. The present Patent Application isrelated to U.S. Pat. application Ser. No. 09/118,683, filed Jun. 30,1998 by Vijay Mathur for A MODULAR AUTOMATED DIAGNOSTIC ANALYSISAPPARATUS WITH A SELF CLEANING SAMPLE INPUT PORT, AN IMPROVED FLUIDSELECTION PORT, AND AN IMPROVED REAGENT PACK, since allowed as U.S. Pat.No. 5,983,734; to U.S. Pat. application Ser. No. 09/350,248 filed Jul.8, 1999 by Vijay Mathur et al. for A FLUID SELECTION VALVE FOR A MODULARAUTOMATED DIAGNOSTIC APPARATUS, allowed and since abandoned; to U.S.Pat. application Ser. No. 09/350,247 filed Jul. 8, 1999 by Vijay Mathuret al. for a FLUID SELECTION VALVE FOR A MODULAR AUTOMATED DIAGNOSTICAPPARATUS, since allowed as U.S. Pat. No. 6,293,162; to U.S. Pat.application Ser. No. 09/350,055 filed Jul. 8, 1999 by Vijay Mathur etal. for A MODULAR SENSOR SYSTEM FOR A MODULAR AUTOMATED DIAGNOSTICAPPARATUS, since allowed as U.S. Pat. No. 6,289,751; and to U.S. Pat.application Ser. No. 09/350,054 filed Jul. 8, 1999 by Vijay Mathur etal. for A REAGENT POUCH FOR USE IN A MODULAR AUTOMATED DIAGNOSTICAPPARATUS, since allowed as U.S. Pat. No. 6,178,832.

FIELD OF THE INVENTION

[0002] The present invention is related to an automated diagnosticanalyzer and, in particular, to an automated diagnostic analyzer capableof accepting biological samples from a variety of sample containers andproviding automatic cleaning of the exterior and interior surfaces ofthe analyzer such that there is no contamination of the analyzer andwith an improved internal fluidic system, an improved valve forintroducing calibrants and air into the fluidic system, a self containedreagent pack capable of storing and handling tonometered calibrants forblood gas determination, and modular film sensors with a record memoryfor storing use life information.

BACKGROUND OF THE INVENTION

[0003] An important and frequently required diagnostic analysis, such asmay be performed in clinical or laboratory medical practice, is theautomated chemical analysis of biological samples, and in particularbiological samples containing whole cells or cellular debris, such aswhole blood, plasma or serum, or other biological fluids wherein theterm fluid includes both liquids and gases. The analysis of biologicalsamples containing cells or cellular debris saves valuable time inreaching a diagnosis and treatment by eliminating the separation step,which can be critical in an emergency situation, and reduces the cost ofeach analysis.

[0004] A major problem in the automated chemical analysis of samplescontaining whole cells or cellular debris, however, is the delivery ofthe samples from a sample container, such as a hypodermic tube, testtube or other sample container, and into the analysis apparatus.Biological samples, and in particular those containing cellularmaterials, have a tendency to leave films containing proteins and otherbiological molecules on the surfaces of the analysis apparatus. As aresult, each of successive samples introduced into the analysisapparatus can simultaneously pick up constituents left on the surfacesfrom previous samples and deposit new constituents, so that a sample canbe contaminated by one or more previous samples. This problem isparticularly acute given the sizes of the samples customarily used insuch analyzers, which are typically in the range of micro-liters.

[0005] These residual films tend to accumulate over time, so that theproblem increases as the number of samples increases, and theinteraction between a given sample and the residual films from previoussamples in unpredictable, depending upon the constituents of the samplesand the composition of the residual films.

[0006] Methods for dealing with this problem as regards the interiorsurfaces of an analysis apparatus have long been available and generallyinvolve regular washing or flushing of the interior passages andchambers of the apparatus through which the biological samples pass. Atypical analysis apparatus will normally use the pumps, tubing andpassages used to move the samples through the device to also move thecleaning solutions through the device, thereby insuring that allinternal surfaces, passages and chambers that come in contact with thesamples also come in contact with the cleaning solutions. These cleaningsolutions range from mild to aggressive, usually containing strongalkaline constituents, such as bleach, or enzymatically activeconstituents, such as proteases. For this reason, many automatedanalysis devices are provided with containers, either located within theapparatus or outside the apparatus itself, for storing cleaningsolutions and the waste products resulting from cleaning operations.

[0007] These cleaning methods are confined to the interior surfaces ofthe analysis apparatus, that is, the surfaces of the passages andchambers through which the samples and reagents flow in passing from thesample entry point to the analysis sensors and the surfaces of theanalysis sensors that are contacted by the samples. It will be noted,however, that the methods of the prior art for cleaning even theinterior surfaces of an analysis apparatus are often inadequate toprevent interaction between a sample and the residue or residual filmsfrom previous samples and there is frequently contamination betweensamples and calibration reagents. In particular, the interior fluidpaths of the analysis apparatus of the prior art frequently include“dead” spaces or voids that trap portions of the samples and fluidsflowing therethrough and such “dead” spaces and voids are difficult toflush out or clean, so that the residues or films trapped in such areasmay in turn contaminate subsequent samples. Such voids and “dead” spacesfrequently occur, for example, in the corners of sharp bends in thefluid paths, in the comers formed where the fluid path changesdimensions and at sliding joints between sections of the fluid path. Inaddition, it is common in analysis apparatus of the prior art that thefluids pass through various moving parts in the path to the analysissensors and such moving parts, such as sliding joints, valves and pumps,frequently contain voids and “dead” spaces that trap residues orresidual films that may contaminate other fluids subsequently flowingthrough the apparatus.

[0008] Further, it is apparent that the samples also contact theexterior surfaces of the apparatus, in particular at or around thesample entry point where the samples first enter an analysis device,such as at the input to an aspirating probe through which the samplesare drawn into the apparatus. Because these surfaces are not interior tothe device, and are therefore not part of the cleaning solution pathwithin the device, the films can build up on these surfaces in arelatively unhindered manner.

[0009] The buildup of films and deposits on the exterior surfaces of ananalysis apparatus, for example, at the sample entry point such as anaspiration probe, have been usually handled in the prior art by havingthe user manually wipe the contaminated surfaces. This method, however,is unsatisfactory for many reasons. For example, not only does themanual cleaning of the apparatus impose an additional task on an alreadytoo busy user, but the user may forget to clean the sample entry asoften as necessary, or at all, with resulting contamination of thesamples. In addition, the user is undesirably exposed to biologicalhazards when manually cleaning the apparatus, such as puncture woundsfrom a contaminated aspiration probe and the sample residues themselves.The user must also safely dispose of the contaminated cleaning supplies,further adding to the cost and inconvenience of analyzing biologicalsamples.

[0010] Another problem in the automated biological analysis apparatus ofthe prior art arises from the need to calibrate the analysis apparatusin order to validate the results of the sample analyses. In this regard,the cost of providing separate means for delivering the calibrationsamples, or calibrantes, and the samples to be analyzed into theapparatus can be unacceptable and, if the calibrante and analysis sampledelivery paths are not substantially the same, the differences in thepaths can introduce systematic errors in the analysis process as regardsthe calibrantes or the samples being analyzed, or both.

[0011] For these reasons, the means by which calibrantes are introducedto the analysis mechanism and sensors is generally the same as that usedto introduce the samples to be analyzed and the calibrantes generallyfollow the same flow path as the samples. This, however, can result incross-contamination between the calibrantes and the samples and thiscross-contamination can be more critical than cross-contaminationbetween samples. This problem is compounded where multiple calibrantesare necessary, as the means by which the calibrantes are introduced tothe apparatus must include the capability of switching among thecalibrantes without cross-contamination among the calibrantes or betweenthe calibrantes and the samples to be analyzed. The problem is furthercompounded in that many current analyzers provide completely automaticcalibration, so that the means by which the calibrantes are introducedare more complex while, at the same time, being less accessible forcleaning.

[0012] Still another problem in the automated biological analysisapparatus of the prior art arises because the biological samples to beanalyzed may be provided in a variety of sample containers, such asVacutainer tubes, syringes, capillary tubes of various sizes, and avariety of types and sizes of sample cups and beakers. While the sampleentry point of the analysis apparatus should be capable of acceptingsamples directly from any of these containers, thereby providing userswith the maximum flexibility as regards the acquisition and storage ofsamples, each different type of sample container places a differentgeometric constraint on the entry point and on the operations by whichthe samples are introduced into the analysis apparatus. This, in turn,has previously significantly increased the cost and complexity of theanalysis apparatus and made the apparatus more complex for the user and,at times, very awkward for the user.

[0013] Yet another problem of the analysis apparatus of the prior art isin the valves used to select and route calibration and cleaning fluids,and perhaps sample fluids, into and through the analysis. In addition tothe problems of the prior art discussed above, the design of such valveshas generally conformed to traditional principles, using traditionalmaterials such as metal or plastic for the body and moving parts of thevalve and using traditional methods such as plastic or rubber seals,such as O-rings and washers, to prevent leakage from or into the valvepassages. Such valves tend to be expensive to manufacture, requiresignificant and frequent maintenance, and generally become unusable dueto wear in a relative short time. In addition, and as discussed above,the traditional designs of such valves frequently include small voids or“dead areas”, as described above, which trap films or residues of thecalibration and cleaning fluids and samples flowing therethrough, so aone fluid or sample may frequently contaminate a subsequent fluid orsample.

[0014] Still another problem of the analysis devices of the prior artconcerns the difficulty and complexity of the operations and actionsrequired of a user of the apparatus, which may be regarded as “ease ofuse” issues. One group of such issued relates directly to the analysisof individual samples and concern the convenience with which a user mayuse the apparatus to analyze a sample. For example, and as discussedabove, the user should be able to present samples to the apparatus froma variety of types of sample containers without the need for specialadaptations or operations to switch from one type of container toanother. In another aspect of this same issue, it has been describedthat the analysis devices of the prior art generally require a user tofrequently manually clean the means by which samples and calibrantes areintroduced into the device, which is an inconvenient and potentiallyhazardous operation that would preferably be eliminated.

[0015] In yet another aspect of ease of use of an analysis apparatus ordevice concerns what may be referred to as the “logistic” aspects of theapparatus, that is, its portability, the ease or difficulty of supplyingthe apparatus with reagents and cleaning or calibration fluids, and theease or difficulty of adapting the apparatus to perform different testsor multiple tests at the same time or to adding new analysis sensors. Itis preferable that the apparatus be modular to the greatest possibleextent.

[0016] To illustrate, such analysis apparatus is generally provided withreplaceable reservoirs, containing calibrants, reagents and cleaningfluid and the replaceable reservoirs are sometimes combined into a unitknown as a reagent or fluids pack. For the case of blood gas analyzers,however, external tanks of calibrated gases are usually required inaddition to the replaceable reagent pack. The elimination of externalcalibration gas tanks and the incorporation of the calibration gasesinto the calibrant solutions within a modular, replaceable andself-contained reagent pack containing all reagents and calibratingsolutions used in the analyses and calibrations, including thecalibrants for gas sensors, is thereby advantageous. Not only would sucha reagent pack be more convenient in that a reagent pack may simply bereplaced as necessary, but the apparatus could be more portable.

[0017] This, however, presents certain problems in the design andconstruction of such reservoirs, or fluid packs, which are rarely orpoorly met by the fluid packs of the prior art. Packs used to store, forexample, calibration fluids used in association with the measurement ofblood gases contain carefully calculated concentrations of gases. Thesecontainers must therefore prevent the escape or absorption of gases forextended periods, including an unknown shelf storage time and traveltime. This requirement is even more stringent when the packs arerequired to be shipped under conditions, such as air freight, where theexternal atmospheric pressure may vary widely, as may the temperature.Another and related effect to be guarded against is the formation of gasbubbles in the containers since the escape of gases from solution willaffect the calibrated concentration of gases in the fluid, even thoughthe gases do not escape the container. Still another problem of theprior art arises from the methods used in the prior art to prevent theescape or absorption of gases from or into a fluid by providing a gastight metal foil liner, such as aluminum foil. While such metal linersare of value in preventing or reducing the escape or absorption of gasesfrom or into a fluid, the metal foil itself may chemically react withthe fluid, thereby destroying or undesirably altering thecharacteristics of the fluid stored therein.

[0018] The present invention provides a solution to these and otherproblems of the prior art.

SUMMARY OF THE INVENTION

[0019] The present invention is directed to a modular automateddiagnostic analyzer having an analysis mechanism chassis for mounting asensor module containing sensors, a fluid entry module for sampleaspiration, a valve module for selecting fluids, a reagent pack forstorage of calibrants, and a pump module for fluidic movement. Theanalyzer includes an improved fluidic system wherein a biological sampledoes not come into contact with the valve system through whichcalibrants and air are introduced to the fluid path, a value systemutilizing an improved design and materials, a self-contained reagentpack containing calibrants, cleaning solution and a waste containerwherein the reagent pack, valve and fluid path are capable of storingand handling tonometered calibrants for blood gas determination,eliminating the need for external tanks of calibrant gases.

[0020] The fluid entry module includes an aspiration tube having a firstsection located within the analysis mechanism chassis for conductingfluids to the sensor chamber and a fluid entry module enclosing a secondsection of the aspiration tube rotatably mounted and rotatably connectedto the first section of the aspiration tube by a fluid and gas tightseal and having a fluid entry port for the entry of fluids to the sensorchamber. The fluid entry module encloses the aspiration tube to rotatewith and to slide along the aspiration tube and includes a wiping sealmounted in the fluid entry module and slidably enclosing the aspirationtube in a region extending from the fluid entry port to move along theaspiration tube, wherein the fluid entry module is rotatably andslidably engaged with the analysis mechanism chassis to move to aplurality of positions whereby a first position locates the aspirationtube entry port adjacent to a nipple for the introduction of calibrationand cleaning fluids into the analysis apparatus. Others of the pluralityof positions present the aspiration tube entry port for the aspirationof fluids into the analysis apparatus from a plurality of differenttypes of sample containers and the motion of the wiping seal withrespect to the aspiration tube entry port removes a residue of theaspirated fluids from the exterior surfaces of the aspiration tube whenthe fluid entry module is returned to the first position, the removedresidue being aspirated into the analysis apparatus for disposal.

[0021] The apparatus also includes at least one sensor module mounted inthe sensor chamber wherein each sensor module includes a sensor modulebody structured to mechanically stack and interlock vertically in thesensor chamber with other sensor module bodies. Each sensor moduleincludes a fluid passage and a sensor element contained in the fluidpassage wherein the fluid passage passes vertically through the sensormodule body and is provided with a fluid tight seal at least one end ofthe fluid passage to form a fluid tight seal with the fluid passage ofanother sensor module body or with a fluid passage into or out of thesensor chamber. Each sensor module also includes electrical circuitry atleast connecting the sensor element with a sensor body connectorengaging with a socket mounted in the sensor chamber and providingelectrical connections to electronics of the diagnostic analyzer.According to the present invention, therefore, the analysis testsperformed on samples by the analysis apparatus can be selected by theselection and insertion of corresponding sensor modules into the sensorchamber. The invention further includes modular film sensors with recordmemories for storing and tracking use life information.

[0022] The analysis mechanism also includes a fluid selection valve forselecting fluids from a selected one of a plurality of fluid sources forintroduction to the entry port. The fluid selection valve includes avalve cylinder having a cylindrical extension extending from and coaxialwith the axis of the valve cylinder to engage in a liquid and gas tightseal with the nipple for engaging with the entry port, and the valvecylinder and the cylindrical extension have a valve cylinder passageextending from the end of the cylindrical extension and along the axisof the cylinder to within the cylinder and therefrom to the rim of thecylinder. The fluid selection valve also includes a value body having avalve well enclosing the valve cylinder such that the valve cylinder canrotate in the well and a plurality of valve body passages extending fromthe inner wall of the valve, the valve body passages intersecting theinner wall of the valve well to align with the valve cylinder passage asthe valve cylinder rotates, thereby allowing the valve cylinder passageto be selectively connected to a selected one of the valve body passagesand a corresponding one of a plurality of fluid sources.

[0023] The apparatus also includes connections to the reagent pack'splurality of fluid sources. The reagent pack of the present inventionincludes one or more reagent pouchs, each pouch having a port body witha port opening therethrough for the extraction of fluid from thecontainers within the reagent pouch, the port opening including anexternal septum providing an external shield protecting from anaccidental opening of the port opening and an internal seal to bepenetrated by a tube leading to the selection valve to permit the fluidstored therein to be selectively extracted from the reagent pouch, theexternal septum providing a generally gas and liquid tight seal aboutthe tube.

[0024] Each fluid container, or pouch, in the reagent pack, in turn,includes at least two walls sealed together along the edges of the sidesto form a liquid container, wherein each wall includes multiple layersof materials wherein at least one layer is a thin, flexible glassmaterial, and a port body with a port opening therethrough from theextraction of fluid from the reagent pouch. In a presently preferredembodiment, each wall is comprised of an inner layer of polyethylene, amiddle layer of a glass material, and an outer layer of PET(polyethylene terephthalate) and the glass material is selected from thegroup of glass materials including a layer of thin, flexible glass, amaterial coated with silicone oxide, or KEVLAR. The port openingincludes an internal septum to be penetrated by a fluid source tubeleading to the fluid selection valve to permit the fluid stored thereinto be selectively extracted from the reagent pouch.

[0025] In addition, the walls of one end of the reagent pouch areextended to form a filler neck wherein during filling of the reagentpouch with a fluid the pouch is filled up to a filler line of the fillerneck and is sealed by heat and pressure applied along a sealing linebelow the filler line so that no bubbles are trapped in the reagentpouch.

[0026] The reagent pack of the present invention may also include a datachip positioned on the reagent pack to be read by a data chip readermounted in the analysis apparatus wherein the data chip stores data tobe read by the analysis apparatus for use in using the fluids stored inthe reagent pouch.

[0027] The fluid entry module engages with the analysis mechanismchassis to control the relative motions and positions of the fluid entrymodule, the aspiration tube and the wiping seal. As such, the fluidentry module is placed in a first, or closed, position so that theaspiration tube is positioned in the first position and the wiping sealis located in a first position adjacent the fluid entry port. The fluidentry module can then be moved to a second position for the introductionof a fluid into the sample entry port from a test tube or similarcontainer, whereby the aspiration tube is rotated to the second positionand the wiping seal is moved along the aspiration tube and away from thefluid entry port, whereupon fluid is introduced into the entry port. Thefluid entry module may then be returned to the first position, wherebythe aspiration tube is rotated to the first position and the wiping sealis moved along the second section of the aspiration tube to the firstposition adjacent the wiping seal adjacent the entry port, so that themotion of the wiping seal removes a residue of the introduced fluid fromthe exterior surface of the aspiration tube when the fluid entry moduleis returned to the first position.

[0028] Further according to the present invention, the analyzer furtherincludes a pump for aspirating fluids through the aspiration tube andsensor chamber and a switch for sensing the position of the fluid entrymodule and activating the pump when, or just before, the fluid entrymodule is returned to the first position. The action of the wiping sealcauses the residue of the introduced fluid to accumulate on the exteriorsurface of the aspiration tube adjacent the fluid entry port as thefluid entry module is returned to the first position, so that theoperation of the pump then draws the accumulated residue of theintroduced fluid through the aspiration tube for disposal.

[0029] Still further according to the present invention the fluid entrymodule may be moved to a third position, so that the aspiration tube isrotated into a third position for the introduction of a fluid from acapillary tube or similar container, while the wiping seal remains inthe first position adjacent the fluid entry port as the aspiration tubeis rotated into the third position. According to the present invention,the interior of the wiping seal adjacent the fluid entry port is shapedto receive and form a fluid and gas tight seal with the capillary tubeor similar container. In addition, the upper interior portion of thewiping seal is shaped at the juncture between the interior circumferenceof the wiping seal and the exterior surface of the aspiration tube suchthat a bead of a last aspirated fluid forms at the junction to functionas a lubricant for motion of the wiping seal along the aspiration tube.

[0030] In an embodiment of the present invention, the aspiration tube iscomprised of a first section located within the analysis mechanismchassis for conducting fluids to the sensor chamber and a second sectionenclosed within the fluid entry module and rotatably connected to thefirst section by a fluid and gas tight seal.

[0031] And still further, the fluid entry mechanism includes a valvehaving a nipple located adjacent the fluid entry port and engaging withthe wiping seal in a fluid and gas tight joint when the fluid entrymodule is in the first position for selectively connecting selected onesof a plurality of calibration/cleaning sources to the nipple for theintroduction of calibration/cleaning fluids to the aspiration tube andsensor chamber.

[0032] The calibration and cleaning fluids may also include gases, suchas air.

[0033] In a presently preferred embodiment, the valve cylinder andcylindrical extensions are a highly polished ceramic material and thevalve body is likewise made of a highly polished ceramic materialfitting with the valve cylinder to form a sliding liquid and gas tightseal, or of a resilient plastic material having an interference fit withthe valve cylinder to form a sliding liquid and gas tight seal with thevalve cylinder. In other embodiments, using either ceramic or plasticmaterials for the valve body, the seal between the valve body and thevalve cylinder may be provided by a separate, resilient sealing cement,such as an O-ring.

[0034] In the presently preferred embodiment, the analyzer apparatus isconfigured with the valve being fluidically before the entry portmechanism. This positioning allows only reagents to flow through thevalve, and the biological samples to be analyzed are introduced at theentry port following the valve, so that no biological fluids passthrough the valve. This apparatus configuration provides a minimalnumber of dead volumes where biological samples can become contaminatesfor future reagents and samples, especially eliminating thecontamination issues associated with biological samples flowing throughvalves where dead volumes typically exist.

[0035] Further according to the present invention, a sensor module mayinclude an internal reservoir in association with the sensor element forstoring fluids for use in operation of the sensor element and willgenerally include a body extension extending forward from the sensormodule to be grasped by a user for insertion or removal of the sensormodule from the sensor chamber.

[0036] According to the present invention, the sensor chamber includesan engagement element for selectively exerting pressure along a stack ofone or more modular sensor modules in the sensor chamber to force themodular sensor modules into contact so that the fluid seals between thefluid passages of the modular sensor modules form a single gas andliquid tight passage through the sensor chamber.

[0037] Also, at least certain of the sensor modules are constructed to astandard width and a standard height while others of the sensor moduleshave widths or heights that are multiples of the standard width andheight and at least certain of the modular sensors modules are dummymodules not having a sensor element but providing a gas and liquid tightfluid passage along the sensor chamber.

[0038] Other features, objects and advantages of the present inventionwill be understood by those of ordinary skill in the art after readingthe following descriptions of a present implementation of the presentinvention, and after examining the drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

[0039]FIG. 1A is an exploded diagrammatic view of an analysis apparatusembodying the present invention and a detailed view of the aspirationtube thereof;

[0040]FIG. 1B is a diagrammatic view of the aspiration tube of theapparatus of the present invention;

[0041]FIG. 1C is an expanded, diagrammatic and perspective view of afluid selection valve of the present invention and the associatedelements for passing selected liquids and gases into the aspiration tubeof the apparatus;

[0042]FIG. 1D is a diagrammatic cross section view of the fluidselection valve of the present invention and the associated elements ofthe present apparatus;

[0043]FIGS. 2A and 2B are views of the fluid entry module of the presentinvention;

[0044]FIG. 3 is a side view of a portion of the analysis mechanismchassis of the present invention.

[0045]FIG. 4 is a diagrammatic view of the analysis mechanism chassis,the fluid entry module and the aspiration tube in the first, closedposition;

[0046]FIGS. 5A through 5C are sequential diagrammatic views of theanalysis mechanism chassis, the fluid entry module and the aspirationtube moving to a third position;

[0047]FIGS. 6A through 6C are sequential diagrammatic views of theanalysis mechanism chassis, the fluid entry module and the aspirationtube moving to a second position;

[0048]FIG. 7 is a cross-section view of the wiping seal of the presentinvention;

[0049]FIGS. 8A and 8B are diagrammatic perspective views of sensor anddetector modules of the apparatus of the present invention;

[0050]FIG. 8C is a diagrammatic cross section view of a sensor module ofthe present invention;

[0051]FIGS. 8D and 8E illustrate a film sensor while FIGS. 8F, 8G and 8Hillustrate examples of film sensor construction, FIGS. 8i, 8J and 8Killustrate arrangements of film sensor modules in a sensor chamber andFIG. 8L is a block diagram of an exemplary record memory;

[0052]FIG. 9A is a diagrammatic view of a reagent pack of the presentinvention;

[0053]FIGS. 9B to 9D are views of a port of a reagent pack of thepresent invention;

[0054]FIG. 10 is a cross section views of single and double walls of areagent pack of the present invention; and,

[0055]FIG. 11 is a perspective view of the modular automated diagnosticapparatus of the present invention.

DESCRIPTION OF THE INVENTION

[0056] Referring to FIGS. 11 and 1A, therein is shown a diagrammaticillustration of an Analysis Apparatus 10 incorporating the presentinvention. Analysis Apparatus 10 is shown therein as generally comprisedof a Fluid Entry Mechanism 12 and an Analysis Mechanism 14.

[0057] As illustrated in FIG. 1A, Fluid Entry Mechanism 12 includes aAspiration Tube 16 a for drawing, or aspirating, fluids includingsamples and calibration and cleaning solutions and gases such as airinto Analysis Apparatus 10 wherein Aspiration Tube 16 a is a hollow tubehaving an Entry Port 18 for the aspiration of the fluids. AspirationTube 16 a extends from Entry Port 18 and to Passage Pivot 20, whereuponit enters Aspiration Tube Passage 22 a leading towards AnalysisMechanism 14. As shown, Passage Pivot 20 is a generally cylindricalmember having Aspiration Tube Passage 22 a extending along itslongitudinal center line from at least the entry point of AspirationTube 16 a to an opening in the center of a Connecting End 24 of PassagePivot 20.

[0058] It will be noted that, shown in FIG. 1B, Aspiration Tube 16 a iscurved through approximately 90° to enter Aspiration Tube Passage 22 aand extend along the longitudinal axis of Aspiration Tube Passage 22 atowards Connecting End 24 a of Passage Pivot 20, thereby providing acontinuous, smoothly contoured passage extending from Entry Port 18 tothe end of Aspiration Tube 16 a in the region of Connecting End 24.Aspiration Tube 16 a thereby provides a passageway for the maximum,efficient transfer of fluids with the minimum entrapment of residualquantities of the fluids in the passage, as may occur, for example, atsharp corners, joints or voids along the passage.

[0059] In a present embodiment of Analysis Apparatus 10, Aspiration Tube16 a is constructed, for example, of stainless steel, polyethylene orpolycarbonate and has an interior diameter of 0.032 inches and anexterior diameter of 0.042 inches to 0.063 inches. Passage Pivot 20, forexample, is constructed of Delrin and has a “D” shaped cross-sectionwith an outside radius of 0.125 inches and an overall length of 1.55inches with Passage Pivot 20 being designed to accept and holdAspiration Tube 16 a.

[0060] As shown in FIG. 1A and in further detail in FIG. 1B, AspirationTube 16 a does not, in the present embodiment of the invention, extendalong Aspiration Tube Passage 22 a entirely to Connecting End 24 a butinstead terminates within a flexible gasket or seal, indicated as Seal26, located within an expanded section of Aspiration Tube Passage 22 aat Connecting End 24 a. Seal 26 and the opening therethrough thatreceives Aspiration Tube 16 a and provides passage for fluids are, likeAspiration Tube Passage 22 a, centered on the longitudinal axis ofPassage Pivot 20. Seal 26 is made, for example, of butyl, viton, orsilicon, and has, for example, an outside diameter of 0.094 inches andan interior diameter of 0.032 to 0.042 inches, depending upon theexterior diameter of Aspiration Tube 16 a.

[0061] As illustrated in FIG. 1A, the passage for the transfer ofsamples, calibrantes and cleaning solutions continues into AnalysisMechanism 14 and to a Sensor Chamber 28 containing the elements forsensing the constituents of the samples. As illustrated in furtherdetail in FIG. 1B, the passage within Analysis Mechanism 14 is providedthrough an Aspiration Tube 16 b, which is contained within acorresponding Aspiration Tube Passage 22 b, wherein the open end ofAspiration Tube 16 b adjacent Connecting End 24 is aligned withAspiration Tube 16 a and the other end of Aspiration Tube 16 b issmoothly bent through an angle to connect with Sensor Chamber 28.Aspiration Tube Passage 22 b follows the same general path as AspirationTube 16 b, but need not be continuously curved and may therefore becomprised of straight line segments formed in the body of AnalysisMechanism 14 by drilling or casting. As in the instance of AspirationTube 16 a, therefore, Aspiration Tube 16 b thereby provides a passagewayfor the maximum, efficient transfer of fluids with the minimumentrapment of residual quantities of the fluids in the passage, as mayoccur, for example, at sharp comers, joints or voids along the passage.

[0062] As illustrated in FIG. 1B, the end of Aspiration Tube Passage 22b nearest Connecting End 24 b is enlarged to receive a section ofPassage Pivot 20, such as Connecting End 24 a, to a depth, for example,of 0.75 inch, so that Passage Pivot 20 rotates around the longitudinalaxis defined by the longitudinal axis of Aspiration Tube Passages 22 aand 22 b. As also illustrated in FIG. 1B, Aspiration Tube 16 b extendsinto this expanded section of Aspiration Tube Passage 22 b, for example,for a distance of 0.25 inch, to extend into the central opening throughSeal 26 to nearly mate with the corresponding end of Aspiration Tube 16a. As has been described, Seal 26 is of a resilient material and has aninterior opening therethrough of approximately the same internaldiameter as the internal diameters of Aspiration Tubes 16 a and 16 b, sothat the interior diameter of the passage through Seal 26 between theends of Aspiration Tubes 16 a and 16 b will be approximately the same asthe interior diameters of Aspiration Tubes 16 a and 16 b. Thisconstruction thereby provides a gas and fluid tight rotating seal thatallows Aspiration Tube 16 a to rotate with respect to Aspiration Tube 16b, but without requiring precision machining or precise measurement andfitting of the components and while minimizing any voids, joints or deadspaces formed the rotating joint. This construction thereby againprovides a passageway for the maximum, efficient transfer of fluids withthe minimum entrapment of residual quantities of the fluids in the fluidpassageway, as may occur, for example, at sharp corners, joints or voidsalong the fluid passageway.

[0063] As indicated in FIG. 1A, the samples, calibrantes and cleaningsolutions are drawn through Aspiration Tubes 16 a and 16 b and throughSensor Chamber 28 by means of a Pump 30 that is connected to theopposite end of Sensor Chamber 28 from Aspiration Tube 16 b and to anExit Port 32 which ultimately leads to one or more waste receptacles forreceiving the fluids, such as samples, calibrantes and cleaningsolutions. In present embodiments of Analysis Apparatus 10, SensorChamber 28 may contain, for example, Ion Selective Electrodes, O₂Electrodes, or CO₂ Electrodes for analyzing electrolytes or blood gasesin blood samples. Pump 30 is preferably comprised of a peristaltic pumpthat moves fluids by moving an occlusive seal along flexible tubing, inthe manner well known and understood by those of ordinary skill in therelevant arts.

[0064] It will be apparent from the above that the design of theaspiration tube passages and sensor chamber of the present invention issuch that the samples, the calibration fluids and the cleaning fluidsall flow through the same interior passages and that these interiorpassages contain no dead areas or volumes to trap the fluids flowingthrough the passages. In particular, it will be noted that while thepassages do contain certain joints or junctures, all of the joints orjunctures are of a rotating nature rather than joints or juncturesallowing axial motion, thereby minimizing or eliminating the dead zonesof voids arising from sharp bends in the passages or sudden changes inthe diameters of the passages. The interior passages of the analysisapparatus of the present invention are thereby designed to prevent orsignificantly reduce the risk of contamination or carryover of one fluidby another.

[0065] Referring again to Fluid Entry Mechanism 12, as described above,Passage Pivot 20 and thus Aspiration Tube 16 a are rotatable around thelongitudinal axis of Passage Pivot 20 and Connecting End 24 b. Asindicated in FIG. 1A, Passage Pivot 20 and Connecting End 24 b andAspiration Tube 16 a can thereby be rotated until Entry Port 18 ofAspiration Tube 16 a is aligned with, and in close proximity to, theopen end of a Calibration/Cleaning Passage 34 that extends from a fluidselection valve, described in further detail below, and terminates in astationary plastic Nipple 38 that provides a tight gas and liquid sealbetween the rotating Calibration/Cleaning Passage 34 and the stationaryNipple 38.

[0066] As shown in greater detail in FIG. 1C, which is an enlargedperspective view of Nipple 38, Calibration/Cleaning Passage 34 and thefluid selection valve of the present apparatus, the Calibration/CleaningPassage 34 continues therethrough to intersect with a Port 40 on theouter face of cylinderical Valve Cylinder 44, so that the rotation ofValve Cylinder 44 will bring Rim Port 40 into alignment with selectedones of one or more Calibration/Cleaning Sources 46, which are fluidpassages leading to one or more corresponding reservoirs for storingcalibration fluids and cleaning solutions. The rotational position ofValve Cylinder 44 is controlled by a Valve Motor 48, so that Rim Port 40and Calibration/Cleaning Passage 34 can be aligned with and therebyjoined with any selected one of Calibration/Cleaning Sources 46, whichmay include a passage or opening to the air. As such, it is possible tointroduce fluids or air from Calibration/Cleaning Sources 46 into EntryPort 18 and thus into the apparatus in any sequence that is desired ornecessary for operation of the apparatus.

[0067] In this regard, it should be noted that Calibration/CleaningSources 46 will preferably include one more Calibration/Cleaning Source46 than the number of calibration fluids and cleaning solutions to beused and that this addition Calibration/Cleaning Source 46 will be opento the ambient atmosphere so that air can be aspirated through the fluidpath in the apparatus. For example, if the sensors residing in SensorChamber 28 are of the types having Nemstian or logarithmiccharacteristics with a non-zero offset, then two calibration solutionswill be required, and probably one cleaning solution, so that the totalnumber of Calibration/Cleaning Sources 46 will be 4, the fourthCalibration/Cleaning Source 46 being the connection to the atmosphere.

[0068] The provision of air as a Calibration/Cleaning Source 46 serves anumber of purposes in Analysis Apparatus 10. First, a “slug” of air maybe aspirated through the system between each fluid that is drawn throughthe apparatus, that is, between the calibration fluids, the cleaningsolutions and the samples, in whatever sequence the fluids are passedthrough the apparatus, and the surface tension at the various fluid-airinterfaces will assist in removing the fluid remnants from the internalsurfaces of the apparatus. Further in this regard, the movement ofair-fluid interfaces through an analysis apparatus have been proven tobe effectively for general cleaning of the apparatus. Still further,separating the different fluids by air slugs prevents mixing between thefluids and thereby preserves the identities and purity of the differentfluids. Finally, the use of air as a “filler” between the fluids toassist in moving the fluids through the apparatus may reduce the amountsof the fluids required, thereby conserving the fluids, allowing analysisof smaller samples, and reducing the costs of using the apparatus.

[0069] Finally, and as represented in FIG. 1A, the operation of AnalysisApparatus 10 is controlled by a Microprocessor Control Unit 50, which isconnected to an associated Control and Display 52, to the sensors inSensor Chamber 28, to Pump 30, and to Valve Motor 48, in the manner andfor the operations that are well understood by those of ordinary skillin the relevant arts.

[0070] Now considering further aspects of the physical construction ofAnalysis Apparatus 10, it is indicated in FIG. 1A that the components ofAnalysis Mechanism 14 are constructed in or as part of an AnalysisMechanism Chassis 54, which forms a base and casing for AnalysisApparatus 10. The general outline and configuration of AnalysisMechanism Chassis 54, which will be described further below, isindicated in FIG. 1A in phantom lines and it will be understood by thoseof ordinary skill in the arts that Analysis Mechanism Chassis 54 mayhave a number of physical configurations, depending upon the layout andlocation chosen for the components of Analysis Apparatus 10, and may beconstructed from a number of materials, such as aluminum, polycarbonateor acrylic. Analysis Mechanism Chassis 54 may be constructed by molding,casting or machining and drilling, or by any combination of suchoperations, and may be constructed of a variable number and layout ofcomponents, again depending upon the specific layout and design that ischosen.

[0071] In a present embodiment, for example, and as generally indicatedin FIG. 1A, Analysis Mechanism Chassis 54 is constructed of aluminum andpolycarbonate and is generally L shaped with an upright body, to theright, containing Connecting Tube 26, Entry Passage 20, Sensor Chamber28, Pump 30 and Exit Port 32. The reservoir or reservoirs connected fromExit Port 32 may be located in the main body of Analysis MechanismChassis 54 and will generally be removable for disposal. Sensor Chamber28 may further be implemented as a replaceable component containing thesensors and the plug-in electrical connections necessary to connect thesensors to the electronic components of Analysis Apparatus 10 and havingpassages mating to Entry Passage 20 and connecting to Pump 30.

[0072] Further in this regard, it will be noted that both Pump 30 andthe valve assembly comprising Valve Cylinder 44 and its associatedstructures are illustrated in FIGS. 1A and 1C in diagrammatic form andas exploded out of the Analysis Mechanism Chassis 54 for purposes ofdescription of the structure and operation of the apparatus and that thereservoir or reservoirs connected from Exit Port 32 are not shown, forpurposes of clarity. Pump 30, however, and for example, is preferablylocated in the lower part of the body, below Sensor Chamber 28 and oneor more of Entry Passage 20, the passage to Pump 28, and the passage toExit Port 32 may be implemented as passages drilled or cast in the bodyof Analysis Mechanism Chassis 54.

[0073] Further in this regard, in a presently preferred embodiment ofAnalysis Apparatus 10 the Calibration/Cleaning Source 46 selection Valve47 is shown in FIGS. 1A and 1C and an alternate embodiment in a crosssection diagrammatic view, that is, schematically and not to dimensionor proportion, in FIG. 1D, includes Valve Cylinder 44 and Nipple 38 andthe associated elements and fluid passages associated with ValveCylinder 44, all of which are contained in a lower extension of AnalysisMechanism Chassis 54 that extends leftwards from Analysis Mechanism 14and under Aspiration Tube 16 a and Passage Pivot 20.

[0074] As illustrated in FIG. 1D, Valve Cylinder 44 includes a Shaft 36,which is a cylindrical extension of Valve Cylinder 44 extending alongthe rotational axis of Valve Cylinder 44 from the rotational center ofthe upper face of Valve Cylinder 44 to Nipple 38. Valve Cylinder 44 andShaft 36 contain Calibration/Cleaning Passage 34 for passing selectedfluids through from Port 40 in the outer wall of Valve Cylinder 44 andthrough Calibration/Cleaning Passage 34 to Entry Port 18 through Nipple38.

[0075] In the presently preferred embodiment, Valve Cylinder 44 andShaft 36 are made of a highly polished ceramic material, such asalumina, and Nipple 38 is made of a resilient plastic, for example,DELRIN (Acetal). The upper end of Nipple 38, that is, the end of Nipple38 that is adjacent to Fluid Entry Port 18, is shaped to mate with FluidEntry Port 18 and a sealing member around Fluid Entry Port 18, as willbe described further below. In the present embodiment, Nipple 38 has,for example, a length of approximately 0.125 inch and a diameter ofapproximately 0.073 inch where it mates with Fluid Entry Port 18 and hasthe general shape of a truncated cone with Calibration/Cleaning Passage34 continuing through Nipple 38 and forming an opening in the top centerof the truncated cone.

[0076] Calibration/Cleaning Passage 34 is molded or cast or drilled intoValve Cylinder 44 and Shaft 36 and has an internal diameter ofapproximately 0.040 inches. In the present embodiment, Valve Cylinder 44has an outside diameter of approximately 0.500 inch and a height, orthickness, of approximately 0.200 inch and there is an extension belowValve Cylinder 44 to mate with a drive shaft driven directly orindirectly by Valve Motor 48, the drive shaft engaging extension being adisk having a diameter of approximately 0.560 inch and a height, orthickness, of approximately 0.1875 inch. In the present embodiment, thecylindrical extension comprising Shaft 36 has, for example, a length ofapproximately 0.5626 inch and a diameter of approximately 0.1875 inch. Asection of the upper end of the cylindrical extension forming Shaft 36has a width of approximately 0.12875 inch for a short distance justbelow the mating end to Nipple 38 to provide a bearing surface for therotation of the valve assembly.

[0077] As illustrated in FIG. 1C, Valve Cylinder 44 may be located in acylindrical hole or opening forming Valve Well 56 in the body ofAnalysis Mechanism Chassis 54 with the passages between Port 40 of ValveCylinder 44 and Calibration/Cleaning Sources 46 formed by passagesdrilled or cast into the body of Analysis Mechanism Chassis 54. The sealbetween Port 40 and the fluid passageways through the body of AnalysisMechanism Chassis 54 to Calibration/Cleaning Sources 46 may be formed asin any of the implementations described below.

[0078] It will be recognized that there are a number of ways toimplement the mechanical connection between Calibration/Cleaning Sources46 and Rim Port 40 of Calibration/Cleaning Passage 34. Oneimplementation, shown in FIG. 1D, for example, is to construct the bodyof the valve as a cylindrical Valve Body 49 that is separate from thebody of Analysis Mechanism Chassis 54 that has a cylindrical openinginto which Valve Cylinder 44 fits and that has passageways leading fromPort 40 to openings that are connected to Calibration/Cleaning Sources46. This separate Valve Body 49 may even be formed as a ring aroundValve Cylinder 44 with passages therethrough to mate with Port 40 andwith tubing leading from the passages through the ring toCalibration/Cleaning Sources 46. Valve Body 40 may also be made ofceramic material and the internal diameter of Valve Well 56 such thatthe interior face of the opening therein into which Valve Cylinder 44fits and the outer face of Valve Cylinder 44 are in sliding contact, sothat there is a sliding seal between Port 40 and the inner face of theopening in Valve Body 49 into which Valve Cylinder 44 fits. In theseimplementations, wherein the valve cylinder and the valve well are ofceramic material, the tolerances on the gap between the ceramic partsmust be sufficiently tight so that the sliding seal is liquid and gastight. In the present implementation, this tolerance is in the range of0.000075 to 0.000200 inches.

[0079] In yet another implementation of this embodiment, the Valve Body49 may be made, for example of Teflon, and the sliding seal may beformed by making the diameter of Valve Cylinder 44 slightly larger thanthe interior diameter of the opening in Valve Body 49 into which ValveCylinder 44 fits, whereupon the Teflon comprising Valve Cylinder 44 willcold flow to form a gas and fluid tight sliding fit into Valve Well 56,as is well known in the art. In other possible implementations, thesliding joint between Rim Port 40 and the valve body and the passagesleading through the valve body to Calibration/Cleaning Sources 46 can besealed by providing an O-ring or thimble gasket for a seal between RimPort 40 and the body of the valve.

[0080] It will be apparent from the above that the design of the valveand associated passages of the present invention is such as to containno dead areas or volumes to trap the fluids flowing through thepassages. In particular, it will be noted that while the passages docontain certain joints or junctures, all of the joints or junctures areof a rotating nature rather than joints or junctures allowing axialmotion, thereby minimizing or eliminating the dead zones of voidsarising from sharp bends in the passages or sudden changes in thediameters of the passages. The valve and associated passages of theanalysis apparatus of the present invention are thereby designed toprevent or significantly reduce the risk of contamination of one fluidby another. It will also be noted that in the presently preferredembodiment of the valve of the present invention, the components of thevalve that are subject to wear are made of ceramic material, therebyreducing the wear rate of these components and significantly increasingthe use life of the valve.

[0081] Finally, it will be noted that in yet other embodiments, thevalve may be rotated manually rather than by Valve Motor 48.

[0082] In summary to this point, Analysis Apparatus 10 thereby providestwo paths for conducting samples and and calibration fluids and cleaningsolutions through the apparatus. The first begins at Entry Port 18whereby samples are introduced from various types of sample containersand the second is from Calibration/Cleaning Sources 46 and through thevalve assembly into Entry Port 18 whereby calibrantes and cleaningsolutions are introduced. These paths are thereby identical from EntryPort 18 onwards and are thus identical for all purposes regarding thepassage of samples, calibrantes and cleaning solutions through theanalyzer. That is, the samples to be analyzed, the calibration fluidsand the cleaning solutions all come in contact with the same internalparts and passages of the apparatus, that is, the internal sections ofthe apparatus from Entry Port 18 and onwards through Sensor Chamber 28.

[0083] To illustrate in further detail, the calibration fluids andcleaning solutions are conveyed through the apparatus by aligning EntryPort 18 with Nipple 38 and by controlling Valve Motor 48 to rotate ValveCylinder 44 to align Port 40 with selected Calibration/Cleaning Sources46 in any desired sequence. When each Calibration/Cleaning Source 46 hasbeen selected, Pump 30 will draw the selected calibration fluid orcleaning compound from the selected Calibration/Cleaning Source 46, andthrough the path comprised of Calibration/Cleaning Passage 34,Aspiration Tubes 16 a and 16 b and through Sensor Chamber 28 and Pump 30and out Exit Port 32.

[0084] When samples to be analyzed are to be introduced into theapparatus, Entry Port 18 is rotated away from Nipple 38 by rotatingPassage Pivot 20 to make Entry Port 18 accessible to the sample. Pump 30will then draw the sample through the path comprised of Aspiration Tubes16 a and 16 b, Sensor Chamber 28, and Pump 30 and out Exit Port 32.

[0085] It will be noted with respect to these operations that, asindicated in FIGS. 1A, 8A and 8B, the sensors in Sensor Chamber 28include both at least one Analysis Sensor 58 in, for example, a SensorModule 118, and a Sample Detector 60 in, for example, a Sensor Module118, wherein, as described above, Analysis Sensors 58 are selected, forthe analysis to be performed, to detect and measure the sampleconstituents of interest. Sample Detector 60, in turn, is response tothe presence of air-fluid interfaces in the substances flowing throughSensor Chamber 28. It should be noted that while Sample Detector 60 isillustrated in FIG. 1A as “upstream” of Analysis Sensors 58, SampleDetector 60 may also be located “downstream” of Analysis Sensors 58. Apreferred embodiment would contain two Sample Detectors 60, one upstreamand one downstream of the Analysis Sensors 58.

[0086] As has been described, air may be introduced into the sequence offluids flowing through Analysis Apparatus 10, that is, between eachcalibration fluid, cleaning compound or sample or even at several placeswithin sequential aliquots of the same fluid. Sample Detector 60 detectsthe air-fluid interfaces at the beginning and end of each sample,calibration fluid or cleaning solution and indicates these interfaces toMicroprocessor Control Unit 50, which uses this information to controlthe flow of fluids through Sensor Chamber 28 and the sensing andmeasurement of the fluids thus presented to Analysis Sensors 58. SampleDetector 60, in combination with the provision of air as one of theCalibration/Cleaning Sources 46, thereby insures appropriate positioningof the various fluids with respect to Analysis Sensors 58. It will beappreciated by those of ordinary skill in the arts that various designsare available to implement Sample Detector 60, which exploits thedifferences in physical properties between liquids and gases. Amongthese are those utilizing the optical transmission and reflectionproperties of fluids and gases, electrical conductivity methods, andultrasonic methods.

[0087] Having described the general and detailed design, structure andoperation of Analysis Apparatus 10, the following will now describefurther aspects of the structure and operation of Analysis Apparatus 10with regard the mechanisms by which samples are introduced into AnalysisApparatus 10 from a variety of containers and by which crosscontamination between samples and between samples and calibration fluidsis prevented.

[0088] As has been described above, samples and calibration and cleaningsolutions are introduced into Analysis Mechanism 14 by means ofAspiration Tube 16 a and Passage Pivot 20, which rotate about thelongitudinal axis of Passage Pivot 20 so that Entry Port 18 ofAspiration Tube 16 a is presented either to Nipple 38, and thus toCalibration/Cleaning Sources 46, or to the sample containers. The onlyexterior section of Analysis Apparatus 10 that is thus subject toresidual films and deposits is Aspiration Tube 16 a around and aboveEntry Port 18.

[0089] As indicated generally in FIG. 1A, Aspiration Tube 16 a andPassage Pivot 20 are enclosed in a Fluid Entry Module 62 which is shownin FIG. 3 in cutaway view as seen from the front, using the same generalviewpoint as in FIG. 1A, and in FIG. 4 in right side view, again usingthe same general viewpoint as in FIG. 1A. The side of Fluid Entry Module62 that is shown in FIG. 4 is thereby the side of Fluid Entry Module 62that is adjacent the upper part of Analysis Mechanism Chassis 54.

[0090] As illustrated in FIGS. 2A and 2B, Fluid Entry Module 62 isprovided with a Front Wall 64, a Back Wall 66, a Top Wall 68 and aBottom Wall 70 that together define the generally elongated rectangularbody of Fluid Entry Module 62 with a Longitudinal Opening 72 extendingfrom Side 74 to Side 76 across the width of Fluid Entry Module 62.Longitudinal Opening 72 is thus open along both Side 74 and Side 76 andis terminated at the upper end by Top Wall 68 and at the bottom end byBottom Wall 70.

[0091] A cylindrical Aspiration Tube Opening 78 extends through BottomWall 70 along the longitudinal axis of Fluid Entry Module 62 and has aFirst Part 80 that is slightly larger than the diameter of AspirationTube 16 a and a Second Part 82 that is sufficient diameter to acceptWiping Seal 84, which will be described in further detail below, in apress fit.

[0092] Fluid Entry Module 62 is further provided with a Lower Guide 86protruding from the lower end of Side Wall 76 and an Upper Guide 88protruding from the upper end of Side Wall 76, both generally locatedalong the longitudinal axis of Fluid Entry Module 62.

[0093] As shown in FIGS. 2A and 2B, Passage Pivot 20 is located in aposition within Longitudinal Opening 72 to extend across Fluid EntryModule 62 from Side Wall 76 to Side Wall 74 and, when at the extremeupper position, will abut the inner side of Top Wall 68. Aspiration Tube16 a extends from Passage Pivot 20 and along the longitudinal axis ofFluid Entry Module 62 within Longitudinal Opening 72 to extend throughAspiration Tube Opening 78 and Wiping Seal 84. The length of AspirationTube 16 a and the distance between Top Wall 68 and Bottom Wall 70 issuch that the assembly comprised of Aspiration Tube 16 and Passage Pivot20 are enclosed within Fluid Entry Module 62, but so that Fluid EntryModule 62 can slide longitudinally up and down along Aspiration Tube 16a, while rotating, together with Passage Pivot 20 and Aspiration Tube 16a, about the longitudinal axis of Passage Pivot 20.

[0094] It has been described above, and will be further described below,that Fluid Entry Module 62 and Passage Pivot 20 with Aspiration Tube 16a are to rotate as a unit about the longitudinal axis of Passage Pivot20. For this reason, Passage Pivot 20, as described previously, has a Dshaped cross section with the flat section of the D shape engaging withthe sides of Longitudinal Opening 72 provided by the walls of Side 74and Side 76 so that Fluid Entry Module 62 rotates together with PassagePivot 20 while being free to slide along Passage Pivot 20 in thedirection of and to the extent defined by Longitudinal Opening 72.

[0095] Referring now to FIGS. 3 and 4, therein is shown a partiallycutaway view of Analysis Mechanism Chassis 54 and, in particular, BodyFace 90 of Analysis Mechanism Chassis 54 that is adjacent to Side Wall76 of Fluid Entry Module 62, so that the front of Analysis MechanismChassis 54 and the front of Fluid Entry Module 62 face to the right ofthe figure. Indicated in FIGS. 3 and 4 are Calibration/Cleaning Passage34 terminating in Nipple 38, which is located in the leftwards extendinglower part of Analysis Mechanism Chassis 54.

[0096] As shown in FIG. 3, Body Face 90 of Analysis Mechanism Chassis 54is provided with a First Guide Channel 92 that is cut into Body Face 90of Analysis Mechanism Chassis 54 to a width and depth sufficient toaccept Lower Guide 86. As indicated, First Guide Channel 92 extends fromjust above and adjacent to Nipple 38 and continue upwards on a slanttowards the Front Face 94 of Analysis Mechanism Chassis 54 to a pointslightly in front of and below Entry Passage 20, ending at a point, in apresent embodiment, approximately 0.094 inches distant from the centerof Entry Passage 20 and downwards at approximately 45 degrees. FirstGuide Channel 92 also has a First Opening 96, extending from slightlyabove the bottom end of First Guide Channel 92 and through Front Face 94and of sufficient width to allow the passage of Lower Guide 86.

[0097] Body Face 90 of Analysis Mechanism Chassis 54 has a Second GuideChannel 98 of sufficient depth and width to accept Upper Guide 88 andlocated to accept Upper Guide 88 when Fluid Entry Module 62 rotatesabout Passage Pivot 20 when Passage Pivot 20 is located at the upper endof Longitudinal Open 72, directly abutting Upper Wall 68. Second GuideChannel 98 extends in an approximately quarter circle path around thecentral axis of Passage Pivot 20 and from a point above the central axisof Passage Pivot 20 to a point that is approximately horizontally to therear of Passage Pivot 20, relative to Front Face 94. As shown, SecondGuide Channel 98 has a Second Opening 100 which extends from SecondGuide Channel 98 and directly upwards from the point over Passage Pivot20 to and through Upper Face 102 of Analysis Mechanism Chassis 54.Second Opening 100 is of sufficient width and depth to allow the passageof Upper Guide 88.

[0098] Fluid Entry Module 62 and Aspiration Tube 16 a with Entry Port 18may therefore be located in any of three positions, which may bereferred to as the “closed”, “capillary” and “test tube” positions, andwill follow one path in moving between the “closed” position to the“capillary” position and a second path in moving between the “closed”position and the “test tube” position.

[0099] The “closed” position and the movements of Fluid Entry Module 62and Aspiration Tube 16 a with Wiping Seal 84 to the “capillary” and“test tube” positions are illustrated, respectively, in FIG. 4 and inFIGS. 5A through 5C and 6A through 6C. It will be noted that thestructures and component elements shown in FIGS. 4 through 6C have beenreduced to skeletal form for clarity of representation, that is, onlythe elements most essential to the discussion are shown and all otherelements have been eliminated from these figures.

[0100] Referring to FIG. 4, and to FIGS. 2A, 2B and 3, in the “closed”position, which is the normal “at rest” position for Fluid Entry Module62, Fluid Entry Module 62 is located in the vertical position withrespect to Passage Pivot 20 and Analysis Mechanism Chassis 54 so thatEntry Port 18 of Aspiration Tube 16 a is directly adjacent to and matingwith Nipple 38. It should be noted that, at this point, Fluid EntryModule 62 is located along Aspiration Tube 16 a so that Upper Wall 68 isdirectly abutting Passage Pivot 20. In this “closed” position, WipingSeal 84 is located at the lowest point along Aspiration Tube 16 a,whereupon Wiping Seal 84 forms a seal with Nipple 38 to prevent leakagefrom this joint and the entry of unwanted substances, including air,through this joint. It will also be noted that Bottom Wall 70 preferablyabuts the upper surface of Analysis Mechanism Chassis 54 around Nipple38, with Nipple 38 extending upwards into Aspiration Tube Opening 78 tomate with Wiping Seal 84, so that the lower section of Fluid EntryModule 62 further protects this junction. In another preferredembodiment, Nipple 38 extends upwards into Aspiration Tube Opening 78,and mates with and abuts the inner surface of Wiping Seal 84 in order tominimize any dead volume therein.

[0101] Fluid Entry Module 62 and Aspiration Tube 16 a with Entry Port 18are moved to the “capillary” position, as illustrated in FIGS. 5Athrough 5C, by slightly lifting Fluid Entry Module 62 upwards, that is,sliding Fluid Entry Module 62 along the longitudinal axis of AspirationTube 16 a, to the point illustrated in FIG. 5A where Fluid Entry Module62 can rotate about Passage Pivot 20 in the manner that Lower Guide 86passes out of First Guide Channel 92 through First Opening 96. It shouldbe noted, in this regard, that Lower Guide 86, Upper Guide 88, FirstGuide Channel 92 with First Opening 96 and Second Guide Channel 94 withSecond Opening 100 are preferably located and dimensioned such thatUpper Guide 88 cannot yet pass through Second Opening 100 when LowerGuide 86 has reached the point to pass through First Opening 96. At thispoint in the motion of Fluid Entry Module 62, and as illustrated in FIG.5B, Fluid Entry Module 62 is rotated further around Passage Pivot 20 sothat Upper Guide 88 is trapped in Second Guide Channel 94 and so thatFluid Entry Module 62 cannot slide further along the longitudinal axisof Aspiration Tube 16 a. In addition, and because Fluid Entry Module 62is prevented from sliding further along Aspiration Tube 16 a, the lowersection of Aspiration Tube 16 a, in particular Entry Port 18, will berecessed within Fluid Entry Module 62, and in particular, withinAspiration Tube Opening 78 and within Wiping Seal 84.

[0102] Fluid Entry Module 62 then continues to be rotated about PassagePivot 20 until Entry Port 18 at the end of Aspiration Tube 16 hasreached a point, illustrated in FIG. 5C, convenient for the user topresent the outlet of a capillary tube, hypodermic syringe or similarsample container to Entry Port 18. In the instance of capillary tubes,for example, which are generally open at both ends, Fluid Entry Module62 will generally be rotated until Aspiration Tube 16 a is essentiallyhorizontal so that the sample does not accidentally flow out the otherend of the capillary tube and to insure the proper flow of the sampleinto Entry Port 18.

[0103] The end of the sample container, that is, the open end of thecapillary tube, hypodermic syringe or similar container from which thesample is to be drawn, is then inserted into the opening in Wiping Seal84 and into contact or close proximity with Entry Port 18 so that thesample can be drawn into the apparatus. It should be noted, in thisrespect, that the enclosure of both the open end of the sample containerand Entry Port 18 within Wiping Seal 84 provides a gas and liquid sealedjunction between the sample container and Entry Port 18, insuring thatthe sample is drawn into the apparatus and preventing the entry of airor contaminates.

[0104] Fluid Entry Module 62 and Aspiration Tube 16 a with Entry Port 18are moved to the “test tube” position, as illustrated in FIGS. 6Athrough 6C, by again sliding Fluid Entry Module 62 upwards along thelongitudinal axis of Aspiration Tube 16 a, but in this instancecontinuing to slide Fluid Entry Module 62 upwards past the pointillustrated in FIG. 6A whereby Lower Guide 86 can pass through FirstOpening 96. As this motion continues, Upper Guide 88 will pass out ofSecond Guide Channel 94 through Second Opening 100, while Lower Guide 86is trapped within First Guide Channel 92 and can move only upwards alongFirst Guide Channel 92.

[0105] As Fluid Entry Module 62 continues to slide upwards alongAspiration Tube 16 a, Lower Guide 86 will, as illustrated in FIG. 6B,continue to move upwards along First Guide Channel 92 and First GuideChannel 92, by constraining the motion of Lower Guide 86, will causeFluid Entry Module 62 to slide upwards along Aspiration Tube 16 a and tosimultaneously rotate about Passage Pivot 20 until a significant lengthof Aspiration Tube 16 a has been exposed and Aspiration Tube 16 a hasrotated to an angle, illustrated in FIG. 6C, that is convenient for theuser to present a test tube, cup or similar sample container to EntryPort 18 at the end of Aspiration Tube 16, whereupon the sample isaspirated into Analysis Apparatus 10 as described above.

[0106] Finally, the above described motions of the component parts ofand associated with Fluid Entry Module 62 will be reversed whenAspiration Tube 16 a and Entry Port 18 are returned from the “capillary”or “test tube” positions to the “closed” position.

[0107] It is therefore apparent that the mechanism provided by FluidEntry Module 62, Aspiration Tube 16 a, Passage Pivot 20 and theirrelated channels and guides provides an analysis apparatus that iscapable of conveniently accepting samples from a wide variety of samplecontainers by providing an entry port mechanism with multiple positions,each position being adapted for a different class or type of samplecontainer.

[0108] As will be described just below, this same mechanism alsoprovides a mechanism for automatically, safely and conveniently removingthe residual films and deposits from samples.

[0109] In particular, it has been described above that Wiping Seal 84 isenclosed in Aspiration Tube Opening 78, which extends through BottomWall 70 and that Aspiration Tube 16 a extends through Wiping Seal 84with Wiping Seal 84 sliding along Aspiration Tube 16 a from and to theclosed position as Entry Port 18 is moved from and to the closedposition. As illustrated in FIG. 7, Wiping Seal 84 is essentiallycylindrical and fits closely within Aspiration Tube Opening 78,preferably by an “interference” fit wherein the exterior diameter ofWiping Seal 84 is approximately 0.003 inches greater than the interiordiameter of Aspiration Tube Opening 78, so that Wiping Seal 84 remainsin place in Aspiration Tube Opening 78 as Wiping Seal 84 moves, orslides, along Aspiration Tube 16 a. For example, in a present embodimentof Analysis Apparatus 10 Wiping Seal 84 and Aspiration Tube Opening 78may have respective diameters of 0.248 inch and 0.251 inch.

[0110] The interior of Wiping Seal 84 is similarly generallycylindrical, having a narrower cylindrical upper section for receivingAspiration Tube 16 a and a wider cylindrical lower section for matingwith Nipple 38 and, for example, capillary tubes or syringes. As alsoshown in FIG. 7, the interior of the lower section of Wiping Seal 84,that is, the section of Wiping Seal 84 coming in contact with Nipple 38,is expanded and shaped internally to form a close mating joint withNipple 38, thereby providing a superior seal to Nipple 38 when EntryPort 18 is in the closed position, as defined above. The upper sectionof the interior of Wiping Seal 84, that is, the “downstream” end ofWiping Seal 84 closest to Passage Pivot 20, is further preferablyprovided with one or more internally extending Sealing Ridges 104extending around the circumference of the interior of Wiping Seal 84.

[0111] In a presently preferred embodiment, Wiping Seal 84 is preferablecast or molded from a relatively soft elastomeric material, such assilicon, Viton or butyl rubber, and the inner diameter of Sealing Ridges104 is preferably approximately 10% to 20% smaller than the exteriordiameter of Aspiration Tube 16 a. As such, Sealing Ridges 104 aretherefore elastically expanded by Aspiration Tube 16 a and therebyprovide one or more corresponding seals around Aspiration Tube 16 awhile allowing Wiping Seal 84 to slide along Aspiration Tube 16 a. Itshould be noted, however, that Sealing Ridges 104 are not necessary forproper operation of the apparatus and may be eliminated in alternateembodiments.

[0112] Wiping Seal 84 thereby operates when Entry Port 18 is in theclosed position to retain calibration and cleaning solutions within theinterior fluid passageways of Analysis Apparatus 10, particularly as thecalibration and cleaning solutions are present in the fluid passagewaysonly when the calibration or cleaning solutions are aspirated throughthe apparatus, as discussed above. Residual films and deposits from thecalibration and cleaning solutions are thereby deposited only on theinterior surfaces of the apparatus, and are removed by the cleaningprocess. Further in this regard, it is apparent that residual films anddeposits can be deposited on both the interior and exterior surfaces ofthe apparatus only while Entry Port 18, that is, Fluid Entry Module 62and Aspiration Tube 16 a, are in the “capillary” or “test tube”positions. It is also apparent that residual films or deposits from thesamples will be deposited on the exterior surfaces of the apparatus nearthe tip of Aspiration Tube 16, that is, on Aspiration Tube 16 a at EntryPort 18 and on the exterior surface of Aspiration Tube 16 a betweenEntry Port 18 and the bottom of Wiping Seal 84.

[0113] It has also been described that as Entry Port 18, and thus FluidEntry Module 62 and Aspiration Tube 16 a, are moved from the “closed”position to the “capillary” or “test tube” positions, Wiping Seal 84slides longitudinally along Aspiration Tube 16 a to expose a section ofAspiration Tube 16 a at and above Entry Port 18.

[0114] When a sample has been introduced into the apparatus, Entry Port18, with Fluid Entry Module 62 and Aspiration Tube 16 a, are returned tothe closed position for the subsequent introduction of cleaningsolutions and/or calibration fluids before the next sample isintroduced. As has been described above, the motion of Fluid EntryModule 62 and Aspiration Tube 16 a when returning to the “closed”position are the reverse of their motions when moving to the “capillary”or “test tube” positions, so that Aspiration Tube 16 slides throughWiping Seal 84 to bring Wiping Seal 84 back to at or near the end ofAspiration Tube 16 a, that is, at or near Entry Port 18. Viewed from theother perspective, Wiping Seal 84 effectively slides down AspirationTube 16 a from the “capillary” or “test tube” position to the “closed”position and moves into close proximity with the end of Aspiration Tube16 a while doing so.

[0115] During this motion of returning to the “closed” position from the“capillary” or “test tube” positions, therefore, Wiping Seal 84 “wipes”the exterior surface of Aspiration Tube 16 a, cleaning it of anyresidual film or deposit from the sample, with the residual film ordeposit forming as a drop or bead at or very near the end of AspirationTube 16 a, that is, at or very near Entry Port 18.

[0116] As indicated in FIGS. 1A and 3, Analysis Apparatus 10 furtherincludes a Position Sensor 108 mounted, for example, on Face 90 ofAnalysis Mechanism Chassis 54, to detect when Fluid Entry Module 62 hasrotated to nearly the “closed” position so that Entry Port 18, where atthis point in the motion of Fluid Entry Module 62 the drop or bead ofresidual film or deposit from the sample has formed due to the wipingaction of Wiping Seal 84, is near to but not yet in alignment andcontact with Nipple 38.

[0117] At this point, Position Sensor 108 provides a signal toMicroprocessor Control Unit 50, which activates Pump 30 to draw the dropor bead of sample residue or deposit into the fluid passages of AnalysisApparatus 10, whereupon it is disposed of.

[0118] The analysis apparatus of the present invention thereby providesan automatic system for cleaning residual sample, calibration andcleaning films and deposits from both the interior and exterior surfacesof the apparatus, thereby preventing cross contamination betweensamples, calibration fluids and cleaning solutions. In addition, thecleaning mechanisms of the present invention operate automatically, inparticular to clean the exterior surfaces of the apparatus each time theentry port is returned to the normal, closed position, and withoutrequiring additional work on the part of the user. Still further, thecleaning mechanism of the present invention does not require that theuser manually clean the apparatus, thereby avoiding risk of injury tothe user and damage or contamination to the apparatus, and does notrequire the additional disposal of cleaning waste and materials.

[0119] Lastly, it is shown in FIGS. 3, 4 and 5 that Fluid Entry Module62 and Analysis Mechanism Chassis 54 may additional be provided with amechanism for selecting between operation in the “capillary” and “testtube” positions, thereby reducing the manual dexterity required on thepart of the user in selecting the position of Entry Port 18 whenintroducing a sample into the apparatus. As illustrated therein, FrontWall 64 of Fluid Entry Module 62 is provided with a Selector Channel 110running across Front Wall 64, generally from Side 74 to Side 76 but openon Side 76 and having a T cross section wherein the upright bar of the Tintersects and opens across Front Wall 64 to form an open slot across atleast part of Front Wall 64. A Selector Bar 112 having a corresponding Tcross section and with the upright bar of the T extending out of theSelector Channel 110 slot extending across Front Wall is slidablymounted in Selector Channel 110 to be moved between two positions, onewherein the right hand side of Selector Bar 112 extends to the right ofSide 76 to intersect Face 90 of Analysis Mechanism Chassis 54 and onewherein Selector Bar 112 is moved away from Face 90 such that it doesnot intersect with Face 90. Analysis Mechanism Chassis 54 is providedwith a corresponding Selector Bar Channel 114 in Face 90 and preferablyhaving an L shape as indicated in FIG. 5 with an opening 114 to FrontFace 94 to receive Selector Bar 112 when Selector Bar 112 is slidtowards Face 90. As a result, when Selector Bar 112 is positioned toextend into Face 90, it will enter Selector Bar Channel 114 and preventEntry Port Housing 62 from being rotated until Fluid Entry Module 62 hasbeen moved upwards to the point where Lower Guide 86 cannot escape FirstChannel 92 through Opening 96. As a result, Fluid Entry Module 62 can bemoved only to the “test tube” position when Selector Bar 112 is slid tothe right, but can be moved to the “capillary” position when SelectorBar 112 is slid to the left. It will be apparent to those of ordinaryskill in the arts that the shape of Selector Bar Channel 114 and Opening116 can be implemented in other forms to allow Fluid Entry Module 62 toslide up Aspiration Tube 16 a only to the point whereby Lower Guide 86can be rotated out through Opening 96, thereby allowing Fluid EntryModule 62 to be moved only to the “capillary” position.

[0120] Referring next to Analysis Sensors 58 and Sample Detectors 60, ithas been described above that Sensor Chamber 28 preferably includes atleast one Analysis Sensor 58 and at least one Sample Detector 60 andthat in a presently preferred embodiment of the present apparatus SensorChamber 28 contains two Sample Detectors 60, one upstream and onedownstream of one or more Analysis Sensors 58.

[0121] It has also been described that the Analysis Apparatus 10 of thepresent invention is of modular design and construction to facilitatecleaning and maintenance of the apparatus and the customization oradaptation of the apparatus to specific needs. As represented in FIGS.8A, 8B and 8C, which are perspective views of Sensor Chamber 28 withSensor/Detector Modules 118, this modular construction also extends tothe structure and arrangement of Analysis Sensors 58 and SampleDetectors 60. The modular construction and arrangement ofSensor/Detector Modules 118 and Sample Detectors 60 thereby allowsAnalysis Sensors 58 and Sample Detectors 60 to be readily replaced, forexample, with new Analysis Sensors 58 and Sample Detectors 60, or withdifferent configurations of Analysis Sensors 58 and Sample Detectors 60to meet differing needs.

[0122] As shown in FIGS. 8A, 8B and 8C, Sensor/Detector Modules 118 areeach contained in a Sensor Module Body 118 a designed to mechanicallystack and interlock vertically in Sensor Chamber 28 to form a singleassembly filling Sensor Chamber 28. As illustrated generally in FIG. 8C,which is a generic and diagrammatic cross sectional view of aSensor/Detector Module 118, each a Sensor Module Body 118 a is providedwith a Fluid Passage 120 containing a Sensor Element 122, the type andspecific construction and operation of each Sensor Element 122 dependingupon the type of Sensor/Detector Module 118. As illustrated, each FluidPassage 120 passes vertically completely through the Sensor Module Body118 a from the top side to the bottom side of the Sensor Module Body 118a and is provided with at least one Fluid Passage Seal 124 at least oneend of Fluid Passage 120, being shown in FIG. 8C as an O-ring seal atthe upper end of Fluid Passage 120.

[0123] In the present embodiment, Sensor Chamber 28 includes a sensormodule Engagement Element 118 b, such as a cam or spring element thatexerts a force along a stack of Sensor/Detector Modules 118 so that theFluid Passage Seal 124 at the upper end of the Fluid Passage 120 of eacha Sensor Module Body 118 a is forced into pressure contact with thelower surface of the Sensor Module Body 118 a immediately above, or withthe upper surface of Sensor Chamber 28. Fluid Passage Seals 124 therebyseal the junctions between the Fluid Passages 120 at the junctionsbetween Sensor/Detector Modules 118 and between the topmostSensor/Detector Module 118 and the end of Aspiration Tube 16 b. Finally,it will be noted that the upper end of the passage from Sensor Chamber28 to Pump 30, the input of which is located in the lower face or wallof Sensor Chamber 28, similarly has a Fluid Passage Seal 124 to seal thejunction between the Fluid Passage 120 at the bottom of the lowestSensor/Detector Module 118 and the passage to Pump 30. It may thereforebe seen that the Fluid Passages 120 form a continuous gas and liquidtight passage from Aspiration Tube 16 b to the output to Pump 30.

[0124] As also indicated in FIG. 8C, each Sensor Module Body 118 a mayinclude one or more Sensor Reservoirs 126 that may, for example, containreagents or other fluids used in the operation of the Sensor Element122. Each Sensor/Detector Module 118 may also include Sensor Circuitry128 necessary for the operation of the Sensor/Detector Module 118, whichmay include a complete processing unit with memory and program controland which will include at least the leads to connect the Sensor Element122 to Microprocessor 50 and Display and Controls 52. For this reason,each Sensor/Detector Module 118 will typically include a Connector 130for connecting the leads of the Sensor/Detector Module 118 to a Socket132 mounted to the back wall of Sensor Chamber 28 and providing leads toMicroprocessor 50 and Display and Controls 52 when the Sensor/DetectorModule 118 is plugged into Sensor Chamber 28.

[0125] Finally, it will be noted that each Sensor/Detector Module 118 isprovided with a Protrusion 134 on the front face of the Sensor/DetectorModule 118 to provide a user hand grip by which a user of the apparatusmay insert and remove Sensor/Detector Modules 118 into and from SensorChamber 28. It will be apparent that the insertion of a Sensor/DetectorModule 118 into Sensor Chamber 28 or the removal of a Sensor/DetectorModule from Sensor Chamber 28 will correspondingly make or break contactbetween the Sensor Element 122 electronics and leads and the apparatuselectronics and microprocessor. It will also be apparent that theinsertion or removal of a Sensor/Detector Module 118 may complete ordisrupt the chain of Fluid Passages 120 between Aspiration Tube 16 b andthe outlet to Pump 30, and that it is necessary for each Sensor/DetectorModule 118 location in Sensor/Chamber 28 to contain a Sensor/DetectorModule 118, or an equivalent module providing a sealed Fluid Passage 122in the corresponding location in order to complete the chain of FluidPassages 122 between the end of Aspiration Tube 16 b and Pump 30.

[0126] Lastly in this regard, it will be noted that, as illustrated inFIG. 8B, one or more of Sensor/Detector Modules 118, such as the lowestSensor/Detector Module 118 shown in FIGS. 8A and 8B and designated asSensor/Detector Module 118 c, may have a height or width greater thanothers of Sensor/Detector Modules 118 c. Such a Sensor/Detector Module118 may have a height along the stack of Sensor/Detector Modules 118that is a multiple of a standard Sensor/Detector Module 118 height,either because of functional requirements or to serve as a “filler”module when the available stack height for Sensor/Detector Modules 118in Sensor Chamber 28 is not filled with Sensor/Detector Modules 118. Ina like manner, it will be noted that Sensor Chamber 28 is shown as beingwider than a standardized width of Sensor/Detector Modules 118, and thatSensor/Detector Module 118 c is shown as extending to the right of theother Sensor/Detector Modules 118 and upwards into this additionalspace. This additional width of Sensor Chamber 28 allows the use ofwider than standard Sensor/Detector Modules 118, for example, due tofunctional requirements such as an expanded reservoir for holdingelectrolytes or other fluids used by the sensor.

[0127] It will also be appreciated by those of ordinary skill in therelevant arts that “blank” or “dummy” Sensor/Detector Modules 118 havingonly a Fluid Passage 122 therethrough with the appropriate seals may beprovided and used to fill Sensor/Detector Module 118 spaces not occupiedby functioning Sensor/Detector Modules 118, thereby serving to lock thefunctional Sensor/Detector Modules 118 into Sensor Chamber 28 and toprovide a complete, sealed Fluid Passage 122 between the end ofAspiration Tube 16 b and the passage to Pump 30. Lastly, it will beappreciated by those of ordinary skill in the relevant arts that thefrontal faces of Protrusions 134 may serve to mount or display text orpictorial labels and representations indicating, for example, the typeof Sensor/Detector Module 118 that is installed.

[0128] It will be further appreciated by those of ordinary skill in therelevant arts that one or more of Sensor/Detector Modules 118 maytypically be “reference” modules. An example of such a “reference”module is illustrated in FIG. 8B as the Sensor/Detector Module 118 thatis shown therein as pulled forward out of the Sensor Chamber 28. In thisregard, the particular “reference” Module 118 illustrated in FIG. 8B isshown as having an reservoir or chamber extending to the right of andupwards from the “reference” Module 118 and it will be understood bythose of ordinary skill in the relevant arts that the function of a“reference” electrode is to provide electrical contact with fluidsamples and that this reservoir or chamber maycontain a fluid used inthe reference function. It will also be understood by those of ordinaryskill in the relevant arts that a “reference” sensor or electrode may becontained in a separate “reference” Module 118 or may be included withina Sensor/Detector Module 118 containing one or more Analysis Sensors 58.

[0129] Next considering alternate implementations and embodiments ofSensor Chamber 28, Sensor/Detector Modules 118 and Analysis Sensors 58,new forms of Analysis Sensors 58 based on thick and thin filmtechnologies, sometimes referred to as planar biosensors or planarsensors, have been developed in recent years. Such thick and thin filmplanar sensors offer lower costs, new types of analysis, smallerdimensions and more flexible physical configurations than do previoussensors. Thick and thin film planar sensors have been developed for, forexample, measurement of blood gases, blood electrolytes, glucose andlactate, and for close-to-patient whole blood diagnostics requiring onlysmall sample sizes and are thereby advantageous in a modular AnalysisApparatus 10 of the present invention.

[0130] The general structure of an exemplary Thick Film Planar Sensor(Thick Film Sensor) 172 such as may be employed in Sensor/DetectorModules 118 are illustrated in FIGS. 8D and 8E wherein FIG. 8D is aplanar view of the exemplary Thick Film Sensor 172 and FIG. 8E is across sectional view. As shown therein, a Thick Film Sensor 172 istypically comprised of a Substrate 174 with Sensor Elements 176 formedor mounted thereon within a Chamber 178 having Input and Output Passages180I and 180O for connection into, for example, a Fluid Passage 122.Sensor Elements 176 may include, for example, electrodes, cathodes,anodes, leads, insulating layers and so on, and the Sensor Elements 176residing in a thick film sensor Sensor/Detector Module 118 typicallycomprise one or more multiple use Thick Film Sensors 172. That is, athick film sensor Sensor/Detector Module 118 will typically contain oneor more multiple use Thick Film Sensors 172 rather than the single,single purpose sensor typically found in a conventional Sensor/DetectorModule 118. The Sensor Elements 176 may typically be formed by standardprocesses, such as deposition, screen printing, or chemical or laseretching, and the layers, electrodes, leads and so on may be comprised ofvarious metals, electrolytes, membranes, or other materials, such asinks of various formulations. The Sensor Elements 176 will also includeleads formed on the Substrate 174 for connecting the Sensor Elements 176to a Connector 130 for connecting the leads of the Sensor Elements 176to a Socket 132 mounted to the back wall of Sensor Chamber 28, therebyproviding connections to Microprocessor 50 and Display and Controls 52when the Sensor/Detector Module 118 is plugged into Sensor Chamber 28.In this regard, Connector 130 may be comprised of any appropriate formof connector, including, and most commonly, the leads themselves.

[0131]FIGS. 8F, 8G and 8H illustrate various exemplary constructions ofThick Film Sensors 172 that are either presently commercially availableor that are under development for commercial use and illustrate some ofthe considerations and factors in constructing Thick Film Sensors 172.FIGS. 8F, 8G and 8H respectively illustrate an example of a amperometricThick Film Sensor 172, an example of an oxygen sensing Thick Film Sensor172 and an example of an ion sensitive Thick Film Sensor 172. In theamperometric Thick Film Sensor 172 of FIG. 8F, for example, a platinizedcarbon paste ink is used to screen print the active Electrode 182A inglucose and lactate sensing applications. In glucose and lactate sensingapplications the sensors are relatively free of interference at themaximum expected values of the individual substances to be sensed, whilein enzyme sensing applications the sensor employs an InterferenceRejection Cover Membrane 182I and a Correcting Electrode 182 tocompensate for known interferences. In the oxygen sensing Thick FilmSensor 172 of FIG. 8G, a polymeric perfluorinated ionomer is used as aninternal Electrolyte 182E and is covered by polymer Membrane 182M havinga relatively low permeability for oxygen but a higher permeability towater vapor to allow fast wetting and a stable steady-state response.Lastly, FIG. 8H illustrates an electrode construction in anion-selective Thick Film Sensor 172, such as a sensor for measuringpotassium. In this electrode, a solid internal Contact 182S comprised ofa solid internal electrolyte enclosed in a Membrane 182M, fulfills thefunction of an “internal fill solution” in a conventionalthree-dimensional electrode.

[0132] It has been described above that Sensor/Detector Modules 118containing Analysis Sensors 58 are each contained in a Sensor ModuleBody 118A designed to mechanically stack and interlock vertically inSensor Chamber 28 to form a single assembly filling Sensor Chamber 28.It will be recognized and understood that Sensor/Detector Modules 118containing Thick Film Sensors 172 may likewise be contained in SensorModule Bodies 118A, with the Chamber 178 and the Input and OutputPassages 180I and 180O forming a Fluid Passage 120 in the same manner asin the instance of conventional Analysis Sensors 58. As in the instanceof conventional Analysis Sensors 58, the Fluid Passage 120 formed by theChamber 178 and Input and Output Passages 180I and 180O of a Thick FilmSensor 172 will pass vertically completely through the Sensor ModuleBody 118A from the top side to the bottom side of the Sensor Module Body118A and will be provided with at least one Fluid Passage Seal 124 atleast one end of Fluid Passage 120.

[0133] It will also be recognized, however, that the construction ofThick Film Sensors 172 typically will require different form factorsthan those of Sensor Module Bodies 118A containing conventional AnalysisSensors 58. For example, Sensor Module Bodies 118A containing Thick FilmSensors 172 may typically be “taller” in the vertical axis and“narrower” in the horizontal dimension than Sensor Module Bodies 118Acontaining conventional Analysis Sensors 58, and will accordinglyassemble into Sensor Chamber 28 in different configurations than thoseof Sensor Module Bodies 118A containing conventional Analysis Sensors58. It will also be recognized that Sensor Module Bodies 118A containingThick Film Sensors 172 and Sensor Module Bodies 118A containingconventional Analysis Sensors 58 may be mixed in a Sensor Chamber 28with appropriate selection of the dimensions of the two types of SensorModule Bodies 118A.

[0134] Exemplary arrangements of Sensor Module Bodies 118A areillustrated in FIG. 8I, 8J, 8K. FIG. 8I shows a single stack of SensorModule Bodies 118A containing conventional Analysis Sensors 58paralleled by a single Sensor Module Body 118A containing a Thick FilmSensor 172. FIG. 8J shows a horizontal array of Sensor Module Body 118Acontaining Thick Film Sensors 172, and FIG. 8K shows a vertical stack ofSensor Module Bodies 118A containing conventional Analysis Sensors 58and a single Sensor Module Body 118A containing a Thick Film Sensor 172.It will be understood, however, that there are a very large number ofdifferent possible arrays of Sensor Module Bodies 118A containingconventional Analysis Sensors 58 or Thick Film Sensor 172.

[0135] In this regard, it will be recognized from FIGS. 8I, 8J and 8Kand from the above descriptions that certain arrays of Sensor ModuleBodies 118A containing Thick Film Sensors 172 or Analysis Sensors 58will result in a single Fluid Passage 120 extending vertically throughthe Sensor Module Bodies 118A from the top to the bottom of the SensorChamber 28. Other arrangements of Sensor Module Bodies 118A containingThhick Film Sensors 172 or Sensor Module Bodies 118A may, however,result in multiple Fluid Passages 120 extending vertically through theSensor Module Bodies 118A from the top to the bottom of the SensorChamber 28. In this instance, currently unused ones of the FluidPassages 120 may be blocked with “dummy” Sensor Module Bodies 118A,having a Fluid Passage Seal 124 if necessary, or the Fluid Passages 120may be provided with one or more selection valves similar, for example,to the fluid selection Valve 47 described herein above.

[0136] Lastly in this regard, it will be understood that Sensor Chamber28 will typically again include a sensor module Engagement Element 118b, such as a cam or spring element that exerts a force along a stack ofSensor/Detector Modules 118 so that the Fluid Passage Seal 124 at theupper end of the Fluid Passage 120 of each a Sensor Module Body 118A isforced into pressure contact with the lower surface of the Sensor ModuleBody 118A immediately above, or with the upper surface of Sensor Chamber28. As described, Fluid Passage Seals 124 thereby seal the junctionsbetween the Fluid Passages 120 at the junctions between Sensor/DetectorModules 118 and between the topmost Sensor/Detector Module 118 and theend or ends of Aspiration Tube 16 b. As also described, the upper end ofthe passage from Sensor Chamber 28 to Pump 30 similarly has a FluidPassage Seal 124 to seal the junction between the Fluid Passage 120 atthe bottom of the one or more lowest Sensor/Detector Modules 118 and thepassage to Pump 30.

[0137] A significant difference with Thick Film Sensors 172, however, isthat many Thick Film Sensosr 172 have limited use lives, that is, areoperative or provide reliable results for only a limited number of testsor for a limited period. For example, certain of the Sensor Elements 176of some Thick Film Sensors 172 deteriorate or degrade over time. BecauseThick Film Sensors 172 are essentially sealed units, the Sensor Elements176 or other components of the Thick Film Sensosr 172 cannot bereplenished, refilled, or refurbished, thereby limiting the use life ofthe Thick Film Sensosr 172. In this regard, it will be noted that asdiscussed herein above conventional Analysis Sensors 58 may includeSensor Reservoirs 126 containing, for example, reagents or other fluidsused in the operation of the Sensor Element 122, so that certainelements, such as reagents, can be replenished, replaced or cleaned,thereby extending the user life of some conventional Analysis Sensors58. At least some conventional Analysis Sensors 58, however, may alsohave limited use lives for similar reasons.

[0138] While Analysis Sensors 58 and Thick Film Sensors 172 may berapidly and easily replaced, being modular in structure, it is at leastinconvenient to have a Thick Film Sensor 172, for example, reach the endof its use life without warning during a sequence or series of analysesor at the beginning of a work shift or during a rush or very busyperiod, and may be very disruptive to workflow or to the validity of asequence of analyses. It is also advantageous to know the remaining uselives of Analysis Sensors 58 and Thick Film Sensosr 172 currently in usefor inventory maintenance and replacement ordering purposes.

[0139] For this reason, and as illustrated in FIGS. 8D and 8E, ThickFilm Sensosr 172 further include a Record Memory 184 for storinginformation representing, for example, an identifier of the type ortypes of Thick Film Sensor 172 residing in the thick film sensorSensor/Detector Module 118, a serial number or other identifier of theparticular Thick Film Sensor 172, a “lot” or “batch” number of the ThickFilm Sensor 172, a “use by” date, a maximum number of uses, a currentaccumulated number of test uses, a maximum use period, and a currentaccumulated test use period, calibration information, and so on. Asillustrated, Record Memory 184 is connected to Microprocessor ControlUnit 50 through Connector 130 and leads on the Substrate 174 or leadsintegral with the Record Memory 184. It will be recognized that certainof this information will typically be written into a Record Memory 184during manufacture of the Thick Film Sensor 172 Sensor/Detector Module118, such as an identifier of the type or types of Thick Film Sensor 172residing in the thick film sensor Sensor/Detector Module 118, a serialnumber or other identifier of the particular Thick Film Sensor 172, a“lot” or “batch” number of the Thick Film Sensor 172, a “use by” date, amaximum number of uses, a maximum use period, calibration informationand so on. Other of the information to be stored a Record Memory 184will be generated and written into the Record Memory 184 during use ofthe Thick Film Sensor 172 Sensor/Detector Module 118. For this reason,Microprocessor Control Unit 50 may thereby read the information storedin Record Memory 184, such as the maximum number of uses or the maximumuse period, and may generate and write information into Record Memory184, such as updates of the current number of test uses and the currenttest use period, each time the Thick Film Sensor 172 is used.Microprocessor Control Unit 50 may thereby compare, for example, themaximum number of uses or the maximum use period for a given Thick FilmSensor 172 with the current accumulated number of uses or the currentaccumulated use period each time the Thick Film Sensor 172 is used andprovide a readout or warning when the remaining use period or number ofuses reaches a selected minimum. If the information generated byMicroprocessor Control Unit 50 and stored in Record Memory 184 includes,for example, average rate of use for a given period, MicroprocessorControl Unit 50 could also provide a warning or prediction of theprobable expiration of the Thick Film Sensor 172. It will be recognizedthat a Record Memory 184 may be located at any suitable location in oron a Thick Film Sensor 172, such as on the Sensor Module Body 118A or onthe Substrate 174, and that the input and output connections between theRecord Memory 184 and the Microprocessor Control Unit 50 may be by meansof, for example, a separate connector, additional leads on the Substrate174 and through Connector 130, or additional leads on the Substrate 174and an additional, separate Connector 130.

[0140] An example of a Record Memory 184 in a presently preferredembodiment of Analysis Apparatus 10 is illustrated in FIG. 8L and iscomprised of an EPROM memory chip available from Dallas Semiconductor,such as the DS2502 or DS2505. As illustrated in FIG. 8L, this embodimentof a Record Memory 184 requires only a single Ground 186G lead and asingle Power/Signal 186PS lead but is otherwise a relativelyconventional memory circuit in many respects. The illustrated RecordMemory 184 includes an EPROM 188E, which may be of various capacities,an EPROM Status Memory 188S, an Error Correcting Code Generator 188C, aMemory Control 188M, a Scratchpad Memory 188P, and a ROM 188R forstoring, for example, a chip serial number. As shown, the Record Memory184 circuits further include a Voltage Detect Circuit 190V and aParasite Power Circuit 190P connected from Power/Signal 186PS. When thevoltage on Power/Signal 186PS is within a power range, this is detectedby Voltage Detect Circuit 190V and the voltage on Power/Signal 186PS isrouted to Parasite Power Circuit 190P to charge the power circuit toprovide internal power to the Record Memory 184 circuitry during theread/write of data. When the signal on Power/Signal 186PS is in a dataread/write range, serial control codes and data on Power/Signal 186PSare routed to a Function Control 190F, which controls the operations ofthe Record Memory 184 in the reading and writing of data. Finally, itwill be noted and understood that a Record Memory 184 may be employed inthin film sensor Sensor/Detector Modules 118, which are generallysimilar in construction and operation to Thick Film Sensors 172, as wellas in the conventional Analysis Sensors 58, and in a similar manner andfor similar purposes. It will also be understood that Thick Film Sensors172, or the thin film sensor equivalents, may also include “references”or “reference” electrodes, for the same purposes as in conventionalSensor/Detector Modules 118, and that Record Memories 184 may likewisebe employed in such “reference” thick film Sensors modules or the thinfilm equivalents. In addition, a thick film Module 118 or a thin filmModule 118 may contain a one or more “reference” electrodes in additionto one or moreThick or Thin Film Sensors 172, or may contain only theSensor Elements 176 comprising a “reference” electrode.

[0141] Lastly, it has been described that Calibration/Cleaning Sources46 provide fluid passages leading to one or more correspondingreservoirs for storing calibration fluids and cleaning solutions andthat the outlet of Pump 30 may similarly be led to a reservoir forholding the waste and residue from samples and cleaning and calibrationfluids. As described, Analysis Apparatus 10 of the present invention isof modular design and construction to facilitate cleaning andmaintenance of the apparatus and the customization or adaptation of theapparatus to specific needs and, for this reason, utilizes significantlyimproved reagent packs designed for use in this and similar types ofapparatus, including the apparatus of the prior art.

[0142] Referring to FIGS. 9A and 10, therein are shown diagrammaticrepresentation of, respectively, a Reagent Pouch 136 of the presentinvention and a cross section of the wall structure of a Reagent Pouch136 of the present invention. As illustrated in FIG. 9A, a Reagent Pouch136 has a generally bottle shaped form comprised of a rectangular PouchBody 138 and, extending therefrom, a generally rectangular Filler Neck140. In a typical embodiment, Pouch Body 138 has a volume ofapproximately one liter and is approximately 13 inches high and 8 incheswide while Filler Neck 140 is approximately 5 inches high and 2 incheswide.

[0143] Reagent Pouch 136 may be constructed, for example, by cutting thetwo sides of a Reagent Pouch 136 out of a sheet of multi-layer material,which is described below, and by heat welding the two sides together toform the Reagent Pouch 136 with weld seams along Bottom 142 and Sides144 or by cutting the two sides from the sheet of multi-layer materialas a single piece joined along or side or bottom, folding the doubleoutline together along one side or the base, and welding the remainingseams. For example, the two sides may be cut from the sheet of materialas a joined, base-to-base outline of the two sides and folded along thebase-to-base line so that, when prepared for filling, Reagent Pouch 136would have a fold seam along Bottom 142 and heat welded seams alongSides 144. Whichever method is chosen, Filling End 146 of Filler Neck140 left open to allow the Reagent Pouch 136 to be filled with aselected reagent, cleaning agent or other fluid.

[0144] Also, and as indicated in FIGS. 9A and 9B and 9C, each ReagentPouch 136 is provided with a Pouch Port 145 located, for example, oneside or the bottom of the Reagent Pouch 136 for extracting the enclosedreagent, electrolyte, cleaning agent or other fluid from the ReagentPouch 136. In the exemplary embodiment illustrated in FIG. 9A, PouchPort 145 is located on or near the Bottom 142 seam of Reagent Pouch 136,and adjacent one corner of Reagent Pouch 136. Pouch Port 145 extendsthrough an opening or slit in Pouch Wall 162 of Reagent Pouch 136 withPouch Wall 162 of Reagent Pouch 136 being fitted around and bonded tothe outer rim or surface or Pouch Port 144, for example, by adhesive orheat sealing. FIG. 9B is a front view of a Pouch Port 144 and, as showntherein, Pouch Port 144 has a generally elliptical shape with tear-dropshaped tapered Ends 146 to provide a smooth curve and transition for theportion of Pouch Wall 162 that fits around Pouch Port 144. The shape ofPouch Port 144, and particularly of Ends 146 of Pouch Port 144, therebyavoids forcing an abrupt change in direction of the material of the wallof Reagent Pouch 136 at the point where the wall Reagent Pouch 136 meetsPouch Port 144 and a consequent gap or “wadding” or wrinkling of thematerial at the juncture, which can be difficult to seal and which canbe a source of weakness, both as a joint and in inducing tears in thematerial.

[0145] As illustrated in FIG. 9C, which is diagrammatic cross section ofa Pouch Port 144, Pouch Port 145 is comprised of a Port Body 148 made,for example, of polyethylene or polypropylene, and having a Port Opening150 therethrough for the insertion of a tube, needle or other form ofpassage element therethrough for extracting the fluid from Reagent Pouch136. The outer rim of Port Body 148 is formed into an Engagement Rim 152and, while being represented generically in FIG. 9C, is shaped to engagewith a bracket within the Reagent Pouch Housing 137, an example of whichis shown in FIG. 9D. As is usual and well understood in the field ofart, Engagement Rim 152 operates to engage each Reagent Pouch 136 withthe Reagent Pack 137 and to align Port Opening 150 with a tube, needleor other form of passage element serving to connect the correspondingCalibration/Cleaning Source 46 with the interior of the Reagent Pouch136. Engagement Rim 152, which may be of any suitable shape, therebyoperates to mechanically fix the Reagent Pouch 136 into location in theReagent Pack 137 and to allow the tube, needle or other passage elementterminating Calibration/Cleaning Sources 46 to be inserted through PortOpening 150 and into the Reagent Pouch 136. As shown, Port Opening 150is externally covered with an External Septum 154, which may be, forexample, a thin shield or membrane of the same plastic material used inPort Body 148 or any other suitable material, and which serves toprotect Port Opening 150. The interior of Port Opening 150, in turn, istypically sealed with an Internal Septum 156 which may be comprised, forexample, of metallic foil or, preferably, polyethelene or polyethelenecovered metallic foil, and which serves to additionally seal and protectPort Opening 150. Internal Septum 156 is also designed, as wellunderstood in the relevant arts, to form around the tube, needle orother passage element terminating Calibration/Cleaning Sources 46 as thetube or needle or element is inserted, for example, by deformation ofthe material around the tube or needle, to seal the joint between thetube, needle or other passage element and Internal Septum 156. InternalSeptum 156 thereby operates to prevent the loss of fluid from ReagentPouch 136 or the entry of contaminates into Reagent Pouch 136.

[0146] Lastly in this regard, it is illustrated in FIG. 9D that one ormore Reagent Pouchs 136 are mounted into a Reagent Pouch Housing 137 bymeans of their respective Engagement Rims 152 so that the tubes, needlesor other passage elements terminating the correspondingCalibration/Cleaning Sources 46 may be inserted through their respectivePort Opening 150 s of their Pouch Ports 144. As also illustrated in FIG.9D, each Reagent Pouch Housing 137 is provided with a Data Chip 158mounted on the outer surface of the Reagent Pouch Housing 137 in anarea, for example, adjacent to a Pouch Port 144 or in some othersuitable location. In the presently preferred embodiment, Data Chip 158is a “smartchip” that is used to store information regarding thecontents of the Reagent Pouch Housing 137 to which it is affixed, suchas an identification of the liquid or liquids stored in the ReagentPouch 136 and its particular characteristics, such as the volume andconcentration of the components of the liquid or liquids, the date ofmanufacture, a manufacturer's identification number, and so on. EachData Chip 158 is readable by a suitable corresponding scanner or readermounted in the Analysis Mechanism Chassis 54 in an area or location forholding a Reagent Pack 137, and in a position to be able to read thecontents of the Data Chip 158 affixed to a Reagent Pack 137. There maytherefore be a Data Chip 158 for and adjacent to each possible ReagentPouch 136 location in the apparatus.

[0147] Referring now to the material comprising the walls of ReagentPouch 136, it has been described previously that there are several majorproblems of the prior art regarding the use of Reagent Pouchs 136. Forexample, in the present embodiment the fluids contained in the ReagentPouchs 136 may include tonometered fluids, such as calibrants, composedof an electrolyte solution of known concentrations of salts, anddissolved gases of carbon dioxide, oxygen and an inert gas of knownconcentrations. One problem is preventing the escape of gasses from aprepared calibration fluid or test reagent, or the entry of unwantedgases, particularly during storage or transportation. Another is toavoid contact between the prepared calibration fluid or test reagent andcertain of the materials commonly used to construct reagent pouches,such as the aluminum foils often used to prevent the escape of gasesfrom the enclosed liquids, as such contact frequently results inunwanted chemical reactions. Yet another problem is that it is oftendifficult to obtain the necessary seals between the aluminum or othermetal foils and the layers of plastic materials commonly used toconstruct reagent pouchs, thus resulting in another source of gas leaksfrom and into the pouchs.

[0148] Accordingly, and according to the present invention asillustrated in FIG. 10, the walls, or sides, of the reagent pouchs ofthe present invention are comprised of multiple layers of materialswherein at least one layer is a thin, flexible glass material or asilicon oxide coated material. Such glass materials have the property ofbeing essentially gas tight for even small gas molecules, therebyproviding an effective barrier to prevent the escape or introduction ofgas from or into the reagent pouch, and of being chemically inert,thereby preventing or avoiding unwanted chemical reactions between thematerial of the reagent pouch and the fluids contained therein.

[0149] In a presently preferred embodiment of the Reagent Pouch 136 ofthe present invention and as illustrated in FIG. 10, a Pouch Wall 162 ofa Reagent Pouch 136 is comprised of three Layers 164 wherein Inner Layer164 a is comprised, for example, of polyethelene, Middle Layer 164 b iscomprised, for example, of a glass material, a material coated withsilicon oxide, such as by a deposition, bonding or fusing process, orKEVLAR, and Outer Layer 164 c is comprised, for example, of PET. Thethree layers are typically bonded together in the manner well understoodin the art to effectively form a single layer material made of the threelayers. It will be noted that, in addition to the other advantagesdescribed above, all of these materials are or may be transparent sothat the contents of the Reagent Pouch 136 are viewable.

[0150] Further, it has been described that a further problem withreagent pouches of the prior art has not only been the loss of dissolvedgases from the fluids contained therein, but the formation ofmicrobubbles of the gases within the pouches by escape of the gases fromsolution in the fluid therein, particularly when the reagent pouches aresubjected to reduced external atmospheric pressures during shipment,such as on an airplane. As well known, this type of loss may occurdespite the use of foil barrier layers to prevent the actual loss ofgases from the pouches and, while the gasses are not lost from thepacks, the concentration of gases within the liquid contained thereinchanges and the value of the liquid as a calibration standard is therebydestroyed.

[0151] Finally, it has also been described that it is necessary, or atleast strongly preferable, that no gases be trapped in a Reagent Pouch136 when it is filled with a liquid as such gases often cause unwantedchanges in the composition of the gases in the liquid over time.According to the present invention, therefore, and as illustrated inFIG. 9A, a Reagent Pouch 136 is filled to a Fill Level 168 that ishigher than a Filling Seal Line 170 when the Reagent Pouch 136 is firstfilled, and the Reagent Pouch 136 is then heat sealed along Filling SealLine 170 by the application of heat and pressure along Filling Seal Line170 in the manner well understood in the art. By overfilling the ReagentPouch 136, therefore, and sealing the pack below the liquid level,therefore, all extraneous gases are excluded from the Reagent Pouch 136by the liquid filling the pouch.

[0152] Finally, FIG. 11 provides a perspective view of an assembledmodular automated diagnostic apparatus of the present invention.

[0153] This concludes a description of presently preferred embodiment ofthe present invention, and, while the invention has been particularlyshown and described with reference to selected embodiments of theapparatus thereof, it will be also understood by those of ordinary skillin the art that various changes, variations and modifications in form,details and implementation may be made therein without departing fromthe spirit and scope of the invention as defined by the appended claims.Therefore, it is the object of the appended claims to cover all suchvariation and modifications of the invention as come within the truespirit and scope of the invention.

What is claimed is:
 1. A modular automated diagnostic analyzer forperforming analysis tests on fluid samples, comprising: an analysismechanism chassis for mounting a modular sensor chamber, the analysismechanism chassis including a fluid passage for conducting fluids to thesensor chamber, and a removable sensor module mounted in the sensorchamber for performing analysis tests on the samples, the sensor modulecontaining one or more multiple use thick film sensors, and a recordmemory.
 2. The modular automated diagnostic analyzer for performinganalysis tests on samples of claim 1, further comprising: a processingunit for reading and writing information pertaining to the sensor modulefrom and to the record memory.
 3. The modular automated diagnosticanalyzer for performing analysis tests on samples of claim 1 wherein:each sensor module includes a fluid passage through a sensor modulechamber containing film sensor elements on a substrate.
 4. The modularautomated diagnostic analyzer for performing analysis tests on samples,of claim 3 wherein: each sensor module is provided with a fluid tightseal at least one end of the fluid passage to form a fluid tight sealwith the fluid passage of another sensor module or with the fluidpassage of the analysis mechanism chassis.
 5. The modular automateddiagnostic analyzer for performing analysis tests on samples of claim 4wherein the sensor chamber further includes: an engagement element forselectively exerting pressure along one or more sensor modules in thesensor chamber to force the fluid seals of the one or more sensormodules into contact and into contact with the fluid passage of theanalysis mechanism chassis so that the fluid passages of the one or moresensor modules form a single gas and liquid tight passage through thesensor chamber.
 5. The modular automated diagnostic analyzer forperforming analysis tests on samples of claim 1, further comprising: afluid entry module rotatably mounted to the analysis mechanism andenclosing the fluid passage for conducting fluids to the sensor chamberand having an entry port for the entry of fluids to the sensor chamberthrough the fluid passage and a wiping seal mounted in the fluid entrymodule and slidably enclosing the aspiration tube in a region extendingfrom the fluid entry port, the fluid entry module being rotatably andslidably engaged with the analysis mechanism chassis to rotate to aplurality of fluid entry positions whereby a sliding motion of thewiping seal with respect to the entry port due to rotation of the fluidentry module between fluid entry positions removes a residue ofaspirated fluids from exterior surfaces of the entry port.
 6. Themodular automated diagnostic analyzer for performing analysis tests onsamples of claim 2, wherein: the information pertaining to the sensormodule includes use life information, the use life information includeone of more of (a) a maximum number of test uses of the sensor module,(b) a maximum test use life of the sensor module, (c) a currentaccumulated number of test uses of the sensor module, and (d) a currentaccumulated test use period of the sensor module.
 7. The modularautomated diagnostic analyzer for performing analysis tests on samplesof claim 2, wherein: the information pertaining to the sensor moduleincludes one or more of (a) an identifier of the sensor module, (b) alot number of the sensor module, (c) an identifier of the types of thickfilm sensors contained in the sensor module, and (d) calibrationinformation pertaining to the thick film sensor contained in the sensormodule.
 8. The modular automated diagnostic analyzer for performinganalysis tests on samples of claim 2, wherein: first certain of theinformation pertaining to the sensor module and residing in the recordmemory is stored in the record memory before use of the sensor module,and second certain of the information pertaining to the sensor moduleand reading in the record memory is generated and stored in the recordmemory during use of the sensor module.
 9. A modular automateddiagnostic analyzer for performing analysis tests on fluid samples,comprising: an analysis mechanism chassis for mounting a modular sensorchamber, the analysis mechanism chassis including a fluid passage forconducting fluids to the sensor chamber, and a removable sensor modulemounted in the sensor chamber for performing analysis tests on thesamples, the sensor module containing one or more multiple use thin filmsensors, and a record memory.
 10. The modular automated diagnosticanalyzer for performing analysis tests on samples of claim 1, wherein:one or more of the one or more multiple use thick film sensors is areference.